configure: Simplify common AM_CPPFLAGS and AM_LDFLAGS to a Makefile.common
configure: Automatically disable bitcoin-qt by default, if dependencies are not met
Merge pull request #3233 from laanwj/2013_11_autoconf

Autoconf improvements
doc: replace DOS with MSYS shell to be more consistent

A plain DOS window doesn't have the right path settings, whereas
the MSYS shell window does.
Space saving in /doc README.

Fixed. Split off build, and bootstrap link.
qt: add Open URI dialog
Merge pull request #3215 from laanwj/2013_11_openuridialog

qt: add Open URI dialog
Merge pull request #3138 from super3/master

Squash README