Allow closing of notifications by clicking on them

Adds a DoClick functions to notification icons made by notification/AddLegacy which changes the time left to display on the notification panel. Useful for when notifications might overlap GUI which is needs to be read or clicked on, but the entire panel is not clickable, which makes you less prone to accidentally close the panel.
Example: http://gyazo.com/15ebbcf7c769a127eee247ad49719c35.gif
Added SetMaterial to DImageButton

from DImage
Materials are now cached again

with DImageButton's inclusion of SetMaterial this now will work
SetMaterial updated
ScissorRect for DModelPanel

Adds a scissor rect to the DModelPanel Paint hook which prevents the
drawn model from "leaking" outside of the area of the DModelPanel which
is being drawn.
Updated DComboBox

Added
* PANEL:GetOptionData( id ) returns data of id
* PANEL:GetSelectedID() returns id of currently selected
* PANEL:GetSelected() returns text,data of currently selected item
Update gm_demo.lua

You can now disable the demo recording icon with gm_demo_icon.
TTT: Replace all traces of the folder "VGUI" with "vgui" (Lua)
TTT: Replace all traces of the folder "VGUI" with "vgui" (VMT)
Allow setting custom column width with AddColumn

Adds a third argument, "width", to AddColumns function. Argument is optional and defaults to 50 to retain compatibility with old code.
Make column for user tags slightly wider

70 felt a bit cramped, 90 looks nice.
Merge pull request #655 from Fuzzik/master

TTT: Replace all traces of the folder "VGUI" with "vgui"

gooey
Fix indentation inconsistencies
Fix indentation inconsistencies
Fix indentation inconsistencies
Merge pull request #656 from YMIndustries/master

TTT: Allow setting custom column width with AddColumn
Fix vehicle third person affecting cameras

When looking through camera, the vehicle third person affects view position. It shouldn't.
Improve DAdjustableModelPanel

* Adds CTRL and SPACE keys to lower or raise the camera position vertically
* LMB now rotates view around the model, holding SHIFT restricts movement to X axis. This isn't perfect, but it is still helpful.
Use Enums instead of numbers
Update spawnicon.lua

* Fixes clicking "Resize" automatically rerendering the icon.
* Remove all trailing whitespace and semicolons.