Minor tweaks to "Memory override" pull request

Memory override #3

Added FAQ/comments

Added IO.FontYOffset. Added asserts.

Remove IO.FontHeight, cached automatically. Added assertions.

Added SetCursorPosX, SetCursorPosY shortcuts

Checkbox() return true when pressed

Moved IMGUI_FONT_TEX_UV_FOR_WHITE define to a variable so font can be changed at runtime

Fixes to allow clean 1-pixel thick lines in more use cases. PixelCenterOffset not the same as previously!

Minor fixes to scrollbar rendering, close button and made checkbox/radio button padding more consistent.

Collapse triangle don't have a shadow unless borders are enabled. ...

Fixed cross that appears when hovering window close button to be perfectly 45 degrees.

Fixed collapsing header border (if borders are enabled) being off the clip rectangle. ...

Tweak demo window.

Added comments

Fixed uninitialised fields in ImBitmapFont (were unused when uninitialised, but still dodgy)

Fixed size/padding of slider grab box for vertical symetry (was 1 pixel too high)

Do not update a variable, which is not used.

Updated URL to new ProggyFonts site

Fixed ImGuiTextFilter triming of leading/trailing blanks. Documented "Filtering" section of demo better.

Fixed resource leaks

Added basic sizes edition in the style editor

Merge branch 'Dadeos-compilation_warnings'

Fix type conversion compiler warnings (from dadeos)

Todo list

Fix mismatched static declaration warning

Converted all Tabs to Spaces ...

Argh

Exposed CalcTextSize(), GetCursorScreenPos() for more advanced fiddling

Added an assertion

Converted all Tabs to Spaces (git diff -w shows an empty diff)

Todo list

Removed unused parameter in demo window code