Addition of display list rendering in WinRT library

The display list rendering is used when scaling within the current page to
enable quicker response.
Addition of zoom in and zoom out control on top app bar.

Also rework of some UI interactions to avoid zooming, text search, etc when
in a specialized view like contents or reflow (webview)
Addition of locking cache for display list in winRT library
Fix error handling in WinRT code (that I broke).

Just before pushing the previous commit of Michaels, I removed
an fz_var, thinking it wasn't required. After discussing it with
him I realise that it was needed, so reintroduce it here with
another error handling tweak. Apologies!
Missing update for slider when page is already rendered.
Add support to build command line tools on MINGW.

Tested with msysgit 1.8.3 environment.
Make common wchar_t / utf-8 conversion functions for MSVC tools.
Tweaks to ink annotation for smoothness.

Patch from "andyhan2000" to make the ink annotations smoother.
Merge branch 'master' of http://git.ghostscript.com/mupdf

Conflicts:
	android/src/com/artifex/mupdfdemo/MuPDFReaderView.java
	android/src/com/artifex/mupdfdemo/PageView.java