Merge pull request #312 from topilski/master

Loading bar doesn't centered #309
Logs button in the status bar
Row numbers in Tree View starts from 1 (as in Table View)
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/robomongo/gui/widgets/LogWidget.cpp
and Right click on empty area in Tree View and Table View doesn't show "Insert Document" #321