doc: README.developer: various of cleanups
doc: README.developer: various of cleanups

Change-Id: Ie9ab9abfd9724e24ea7ace87a38ab77e02504b49
Signed-off-by: Alon Bar-Lev <2e3ceb4d37adc6ae3ccc00d3646e0e0a036ace03@redhat.com>

zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,eayun/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine,yingyun001/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine,eayun/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine