Added a few other mentions of errmsg in the documentation.
Added a few other mentions of errmsg in the documentation.

tmc/mgo,tmc/mgo,DroiTaipei/mgo,tchajed/mgo,Danzeer/mgo,SocialExplorerFork/mgo,gabrielrussell/mgo,jjz/mgo,velocity-toolkit/mgo,mjs/mgo,gabrielrussell/mgo,henrylee2cn/mgo,deafgoat/mgo,velocity-toolkit/mgo,hexadecy/mgo,tmc/mgo,deafgoat/mgo,SocialExplorerFork/mgo,gabrielrussell/mgo,Yottaa/mgo.v2,Danzeer/mgo,DroiTaipei/mgo,dmage/mgo,go-mgo/travis-test,henrylee2cn/mgo,go-mgo/travis-test,raymondjacobson/mgo,mcuadros/mgo,jackspirou/mgo,velocity-toolkit/mgo,mjs/mgo,roamz/mgo,dmage/mgo,mcuadros/mgo,DroiTaipei/mgo,hexadecy/mgo,jjz/mgo,tobyzxj/mgo,mcuadros/mgo,tchajed/mgo,mjs/mgo,go-mgo/travis-test,SocialExplorerFork/mgo,tchajed/mgo,velocity-toolkit/mgo,Yottaa/mgo.v2,Danzeer/mgo,dmage/mgo,jackspirou/mgo,deafgoat/mgo,lucasjo/mgo,henrylee2cn/mgo,dmage/mgo,raymondjacobson/mgo,jjz/mgo,DroiTaipei/mgo,tobyzxj/mgo,tmc/mgo,gabrielrussell/mgo,mjs/mgo,mcuadros/mgo,go-mgo/travis-test,hexadecy/mgo,lucasjo/mgo,tchajed/mgo,raymondjacobson/mgo,tobyzxj/mgo,deafgoat/mgo,lucasjo/mgo,jackspirou/mgo,jackspirou/mgo,jjz/mgo,tobyzxj/mgo,lucasjo/mgo,Danzeer/mgo,raymondjacobson/mgo,hexadecy/mgo,henrylee2cn/mgo,SocialExplorerFork/mgo,Yottaa/mgo.v2,tchajed/mgo,Yottaa/mgo.v2