fixes #146
Added zoom movement by keyboard arrows. Not finished yet [ci skip]
Fixes #140
Fixed partially the memory release of parser
tinyxml frees the memory itself (http://tinyxml.cvs.sourceforge.net/viewvc/tinyxml/tinyxml/tinyxml.cpp?revision=1.98&view=markup) so nothiing more to do. Fixes #111
Fixes #148
Feedback added in case of double frame ids
Merge pull request #155 from stdr-simulator-ros-pkg/gui_zoom_fix

Gui zoom and parser fixes