[maven-release-plugin] prepare release mapdb-0.9.12
[maven-release-plugin] prepare release mapdb-0.9.12

jankotek/mapdb,binarytemple/mapdb,olupas/MapDB,lamfire/mapdb,ffjiao/mapdb,codeaudit/mapdb,morfeo8marc/mapdb,hangum/mapdb,ringoluo/mapdb,mebigfatguy/mapdb,olupas/MapDB,SleimanJneidi/mapdb,pettermahlen/mapdb,sumit784/mapdb,cocosli/mapdb,jankotek/mapdb,jankotek/MapDB,jankotek/MapDB,mebigfatguy/mapdb