Address 1829182: it's true that the popup caret menu has been disabled for these...

Address 1829182: it's true that the popup caret menu has been disabled for these tools.  There's no comment in the code saying why.  I've added an environment variable which re-enables the popup menu when set.  export SYNFIG_ENABLE_POPUP_MENU_IN_ALL_TOOLS=1 to try it, and report your findings back to the bug report as to whether this should be the default or not.

git-svn-id: http://svn.voria.com/code@1127 1f10aa63-cdf2-0310-b900-c93c546f37ac