Allow DX11 renderer to be used with devices with lower feature levels.

Examples: DX11: Remove debug flag (#415)

Commenting asserts

TreeNode/CollapsingHeader: some minor cleanup of that horrible function.

TreeNode/CollapsingHeader: some minor cleanup of that horrible function.

Comments & spacing

Added comment on using PushFont() before building the font (#232)

Demo: some TreeNode layout examples (#414, #282)

TreeNode,CollapsingHeader: sizing fixes to support laying out item on same line before/after (#414, #282)

Internal minor renaming

Examples: Not clearing input data/tex data in atlas (will be required for dynamic atlas anyway). Effectively fix resizing in DX examples. ...

+ Standardized comments.

Replace OS IME (Input Method Editor) cursor on top-left when we are not text editing.

Tweak GetGlyphRangesJapanese() to it is easier to modify

Examples: Header comments.

Examples: Header comments.

Examples: Clarified comments. Removed font merging example from comments.

Examples: Added README into the Visual Studio solution to people are less likely to miss it.

Additional comments for new users

Demo: Tweaked Clipping example.

Demo: Fixed variable shadowing warning.

Fixed int>void* warnings for 64-bits architectures and fancy warnings

Speculative build fix for old versions of Visual Studio compiler

Demo: comments (#414)

Demo: Moved property editor demo to its own mini example applet (#414)

Columns: Added Property Tree demo among tidying up demos (#125, #414)

Columns: Fixed bug with indentation within columns, also making code shorter/faster (#414, #125)

Columns: Undo accidental change from 807d4ff

Merge branch 'master' of https://github.com/ocornut/imgui

Columns:: columns set with no implicit id include the columns count into the id to avoid collisions (#125)

Columns: minor tidying up while investigating severe issues with indenting within columns (#414)