Add SSO state to UI

State for PPOs and SEPARABLE state for Programs now included in the "state" tab on the UI.  Also added some further SSO state tracking and fixed a bug in DRAWABLE state restore code when all drawables are bound to GL_NONE.
Load GL entrypoints on Windows after context creation
cmake: use execute_process rather than exec_program

exec_program is deprecated and execute_process is its replacement.
Update to Dependencies Section

Added an apt-get install command to (hopefully) get all dependencies for building
within Ubuntu 14.04.
Merge pull request #163 from tobin-lunarg/win_ogl_fix

Update GL entrypoints after OGL Context is created on Windows.
Merge pull request #166 from kingtaurus/master

Update to Dependencies Section
Merge pull request #164 from mathstuf/deprecated-cmake-command

cmake: use execute_process rather than exec_program
cmake: Strip whitespace from output of qmake queries