Implementing plugins
Merge remote-tracking branch 'origin/feature/simulation' into slohia

Conflicts:
	src/gripmainwindow.cpp
adding comments for using the plugin infrastructure
modifications to the GripTab interface
modifications to the Grip Tab interface
Merge remote-tracking branch 'origin/feature/simulation' into slohia

Conflicts:
	include/gripmainwindow.h
	src/gripmainwindow.cpp
Merge remote-tracking branch 'origin/feature/tabs' into slohia
Define M_PI in inspector.h
Update inspector tab and treeview so that selected joint is displayed and movable
Minor bug fix in inspector tab
Enabled body position and orientation sliders. Need code optimization though.
Merge branch 'feature/visuals' into sungmoon
Clean-up inspector tab code. Need to implement proper transform for body orientation sliders
Minor clean-up in inspector tab
Enable/disable group boxes according to tree view selection
Cleaning up inspector tab
Finish the inspector tab v.1
Merge branch 'feature/visuals' into feature/tabs
Change labels, set precisions, minor upgrades here and there in inspector tab
Update .gitignore