xtimer: support a negative XTIMER_SHIFT.
xtimer: support a negative XTIMER_SHIFT.

rousselk/RIOT,rousselk/RIOT,aeneby/RIOT,plushvoxel/RIOT,Ell-i/RIOT,Ell-i/RIOT,FrancescoErmini/RIOT,backenklee/RIOT,miri64/RIOT,plushvoxel/RIOT,LudwigOrtmann/RIOT,jasonatran/RIOT,tfar/RIOT,dkm/RIOT,A-Paul/RIOT,mtausig/RIOT,neumodisch/RIOT,MohmadAyman/RIOT,TobiasFredersdorf/RIOT,kYc0o/RIOT,zhuoshuguo/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,RIOT-OS/RIOT,jremmert-phytec-iot/RIOT,cladmi/RIOT,syin2/RIOT,neiljay/RIOT,hamilton-mote/RIOT-OS,wentaoshang/RIOT,asanka-code/RIOT,rousselk/RIOT,biboc/RIOT,kb2ma/RIOT,neiljay/RIOT,katezilla/RIOT,mfrey/RIOT,dkm/RIOT,gebart/RIOT,asanka-code/RIOT,malosek/RIOT,LudwigOrtmann/RIOT,BytesGalore/RIOT,rakendrathapa/RIOT,plushvoxel/RIOT,lazytech-org/RIOT,aeneby/RIOT,dkm/RIOT,katezilla/RIOT,neiljay/RIOT,smlng/RIOT,OTAkeys/RIOT,attdona/RIOT,jremmert-phytec-iot/RIOT,ant9000/RIOT,authmillenon/RIOT,malosek/RIOT,kaspar030/RIOT,smlng/RIOT,neiljay/RIOT,neumodisch/RIOT,adrianghc/RIOT,rakendrathapa/RIOT,x3ro/RIOT,attdona/RIOT,miri64/RIOT,rfuentess/RIOT,yogo1212/RIOT,brettswann/RIOT,rfuentess/RIOT,rajma996/RIOT,attdona/RIOT,gebart/RIOT,Yonezawa-T2/RIOT,BytesGalore/RIOT,beurdouche/RIOT,OlegHahm/RIOT,wentaoshang/RIOT,tfar/RIOT,Josar/RIOT,kerneltask/RIOT,kaleb-himes/RIOT,kb2ma/RIOT,Hyungsin/RIOT-OS,neumodisch/RIOT,malosek/RIOT,wentaoshang/RIOT,BytesGalore/RIOT,OTAkeys/RIOT,mtausig/RIOT,syin2/RIOT,jbeyerstedt/RIOT-OTA-update,FrancescoErmini/RIOT,smlng/RIOT,kb2ma/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,kaspar030/RIOT,basilfx/RIOT,authmillenon/RIOT,adjih/RIOT,basilfx/RIOT,roberthartung/RIOT,gautric/RIOT,Hyungsin/RIOT-OS,thomaseichinger/RIOT,LudwigKnuepfer/RIOT,TobiasFredersdorf/RIOT,ant9000/RIOT,lazytech-org/RIOT,rfuentess/RIOT,OTAkeys/RIOT,rousselk/RIOT,immesys/RiSyn,gautric/RIOT,kbumsik/RIOT,jfischer-phytec-iot/RIOT,asanka-code/RIOT,katezilla/RIOT,wentaoshang/RIOT,ks156/RIOT,x3ro/RIOT,LudwigOrtmann/RIOT,altairpearl/RIOT,mfrey/RIOT,yogo1212/RIOT,syin2/RIOT,FrancescoErmini/RIOT,A-Paul/RIOT,rakendrathapa/RIOT,thomaseichinger/RIOT,altairpearl/RIOT,brettswann/RIOT,smlng/RIOT,dkm/RIOT,Ell-i/RIOT,RIOT-OS/RIOT,basilfx/RIOT,jfischer-phytec-iot/RIOT,neiljay/RIOT,Josar/RIOT,beurdouche/RIOT,neumodisch/RIOT,ant9000/RIOT,Josar/RIOT,gebart/RIOT,thomaseichinger/RIOT,brettswann/RIOT,malosek/RIOT,beurdouche/RIOT,wentaoshang/RIOT,gebart/RIOT,syin2/RIOT,josephnoir/RIOT,alignan/RIOT,dailab/RIOT,dailab/RIOT,shady33/RIOT,asanka-code/RIOT,katezilla/RIOT,rajma996/RIOT,backenklee/RIOT,Hyungsin/RIOT-OS,alignan/RIOT,kYc0o/RIOT,kerneltask/RIOT,toonst/RIOT,MohmadAyman/RIOT,ks156/RIOT,kbumsik/RIOT,rajma996/RIOT,immesys/RiSyn,avmelnikoff/RIOT,altairpearl/RIOT,BytesGalore/RIOT,aeneby/RIOT,zhuoshuguo/RIOT,kb2ma/RIOT,lazytech-org/RIOT,josephnoir/RIOT,Yonezawa-T2/RIOT,altairpearl/RIOT,gebart/RIOT,TobiasFredersdorf/RIOT,OlegHahm/RIOT,A-Paul/RIOT,immesys/RiSyn,smlng/RIOT,dailab/RIOT,kYc0o/RIOT,kaleb-himes/RIOT,hamilton-mote/RIOT-OS,TobiasFredersdorf/RIOT,ks156/RIOT,yogo1212/RIOT,gautric/RIOT,jremmert-phytec-iot/RIOT,Yonezawa-T2/RIOT,rajma996/RIOT,LudwigOrtmann/RIOT,kaleb-himes/RIOT,brettswann/RIOT,kaleb-himes/RIOT,ant9000/RIOT,RIOT-OS/RIOT,hamilton-mote/RIOT-OS,rajma996/RIOT,josephnoir/RIOT,malosek/RIOT,asanka-code/RIOT,shady33/RIOT,LudwigOrtmann/RIOT,Ell-i/RIOT,kbumsik/RIOT,rakendrathapa/RIOT,jbeyerstedt/RIOT-OTA-update,BytesGalore/RIOT,yogo1212/RIOT,josephnoir/RIOT,rousselk/RIOT,rfuentess/RIOT,kaspar030/RIOT,cladmi/RIOT,neumodisch/RIOT,beurdouche/RIOT,josephnoir/RIOT,OlegHahm/RIOT,jbeyerstedt/RIOT-OTA-update,jasonatran/RIOT,kbumsik/RIOT,OTAkeys/RIOT,yogo1212/RIOT,brettswann/RIOT,shady33/RIOT,dkm/RIOT,thomaseichinger/RIOT,LudwigKnuepfer/RIOT,adrianghc/RIOT,x3ro/RIOT,d00616/RIOT,plushvoxel/RIOT,zhuoshuguo/RIOT,Hyungsin/RIOT-OS,jasonatran/RIOT,Yonezawa-T2/RIOT,immesys/RiSyn,kerneltask/RIOT,dailab/RIOT,beurdouche/RIOT,jasonatran/RIOT,authmillenon/RIOT,avmelnikoff/RIOT,rousselk/RIOT,alignan/RIOT,LudwigKnuepfer/RIOT,backenklee/RIOT,mtausig/RIOT,jbeyerstedt/RIOT-OTA-update,x3ro/RIOT,x3ro/RIOT,aeneby/RIOT,Yonezawa-T2/RIOT,biboc/RIOT,backenklee/RIOT,jremmert-phytec-iot/RIOT,d00616/RIOT,cladmi/RIOT,attdona/RIOT,basilfx/RIOT,kaleb-himes/RIOT,toonst/RIOT,kerneltask/RIOT,Josar/RIOT,kaspar030/RIOT,rakendrathapa/RIOT,jfischer-phytec-iot/RIOT,rajma996/RIOT,adrianghc/RIOT,asanka-code/RIOT,altairpearl/RIOT,OTAkeys/RIOT,jasonatran/RIOT,authmillenon/RIOT,rakendrathapa/RIOT,lazytech-org/RIOT,hamilton-mote/RIOT-OS,shady33/RIOT,MohmadAyman/RIOT,Ell-i/RIOT,LudwigOrtmann/RIOT,kbumsik/RIOT,LudwigKnuepfer/RIOT,attdona/RIOT,immesys/RiSyn,attdona/RIOT,adjih/RIOT,kYc0o/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,shady33/RIOT,kerneltask/RIOT,miri64/RIOT,yogo1212/RIOT,miri64/RIOT,MohmadAyman/RIOT,backenklee/RIOT,zhuoshuguo/RIOT,tfar/RIOT,avmelnikoff/RIOT,jremmert-phytec-iot/RIOT,gautric/RIOT,Josar/RIOT,kaspar030/RIOT,roberthartung/RIOT,malosek/RIOT,mtausig/RIOT,brettswann/RIOT,adjih/RIOT,mfrey/RIOT,lazytech-org/RIOT,OlegHahm/RIOT,roberthartung/RIOT,mfrey/RIOT,mfrey/RIOT,alignan/RIOT,neumodisch/RIOT,RIOT-OS/RIOT,d00616/RIOT,wentaoshang/RIOT,jfischer-phytec-iot/RIOT,FrancescoErmini/RIOT,FrancescoErmini/RIOT,alignan/RIOT,thomaseichinger/RIOT,TobiasFredersdorf/RIOT,authmillenon/RIOT,OlegHahm/RIOT,A-Paul/RIOT,ks156/RIOT,syin2/RIOT,rfuentess/RIOT,biboc/RIOT,avmelnikoff/RIOT,FrancescoErmini/RIOT,gautric/RIOT,toonst/RIOT,adjih/RIOT,tfar/RIOT,roberthartung/RIOT,ant9000/RIOT,immesys/RiSyn,shady33/RIOT,Yonezawa-T2/RIOT,authmillenon/RIOT,biboc/RIOT,kYc0o/RIOT,dailab/RIOT,ks156/RIOT,adrianghc/RIOT,d00616/RIOT,roberthartung/RIOT,toonst/RIOT,avmelnikoff/RIOT,MohmadAyman/RIOT,plushvoxel/RIOT,mtausig/RIOT,LudwigKnuepfer/RIOT,cladmi/RIOT,hamilton-mote/RIOT-OS,jremmert-phytec-iot/RIOT,adrianghc/RIOT,RIOT-OS/RIOT,tfar/RIOT,altairpearl/RIOT,jbeyerstedt/RIOT-OTA-update,zhuoshuguo/RIOT,A-Paul/RIOT,MohmadAyman/RIOT,basilfx/RIOT,kb2ma/RIOT,toonst/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,d00616/RIOT,cladmi/RIOT,zhuoshuguo/RIOT,Hyungsin/RIOT-OS,katezilla/RIOT,d00616/RIOT,adjih/RIOT,miri64/RIOT,aeneby/RIOT,jfischer-phytec-iot/RIOT,biboc/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT