Unicode support

This reintegrates the Unicode patches and adds a build recipe for bash.

The third patch removes /etc/profile and /etc/inputrc.default from the msys-core package. It took me several hours to figure out that enabling 8-bit input in /etc/inputrc doesn't work with the stupid MSYS default scripts. So I think we need to provide some sane versions of these in the installer root (if only to set HOME appropriately, and without writing to the installation directory).

These tests are still failing for me:
t1508-at-combinations: 24
t2025-checkout-long-paths: 1
t4015-diff-whitespace: 1
t5000-tar-tree: 2
t5003-archive-zip: 2
t9700-perl-git: 1

Compiled packages are here: https://drive.google.com/file/d/0BxXUoUg2r8ftZUpuSWxRMFVwOXc/edit?usp=sharing