Documentation on new font / texture get api

ImFont::GetTextureData API allow to retrieve 8/32 bits data + lazily load defaults font ...

Examples: OpenGL3 and DirectX11 back to using 32-bits texture solely for
ease of integration.

Mde it optional to new() io.Font - however it stills needs to be loaded.

TAB to spaces

ImDrawList::AddText() allows changing font

Added first-pass of Image() based on #73 + demo

Build fix for GCC/Clang, cannot foward declare a static array?

Comments

Loading TTF file with stb_truetype. Broke setup API slightly. Font baked, packed with space for custom data. Embeds compressed ProggyClean.

Version number

Revert "Reexported proggy_clean_13 in a 256x64 texture (instead of 256x128) and documented exact export parameters" ...

Correct but cause problems because many people don't have 1 BPP PNG loaders

This reverts commit 98a38e2.

Fixed leak on shutdown (fixes #110) + possible uninitialized member.

Reexported proggy_clean_13 in a 256x64 texture (instead of 256x128) and documented exact export parameters

Very minor code/comments tweaks.

Fixed hovering of child windows / combo boxes that extend beyond the root window limits.

Failure in LogToFile() treated at an error (assert) in the absence of another type of error handling.

Renamed some color enums

Checkbox and Radio buttons activate on click-release to be consistent with other widgets and most UI

Fix clipboard pasting into an InputText box not filtering the characters according to input box semantic (number, etc.)

Activating widget bring parent window to front

Fixed clicking on Combo box label.

Avoid marking settings as dirty when window is marked unsaved + minor FocusWindow() optimisation

Dragging outside area of a widget while it is active doesn't trigger hover on other widgets.

Todo items.

InputText() consume input characters immediately (fixes #105)

Version number (fix)

Fixed text input filtering for character in the 128-255 range.

Fix for Clang

Examples: Console:: added support for History callbacks + cleanup to be self contained.

Fixed InputInt() InputFloat() label not declaring their width, breaking SameLine (bug #100) ...

+ shallow cleanups