Bundle application launcher script, don't bail out for D-Bus

Set DBUS_FATAL_WARNINGS=0, the stack needs libdbus right now because
of at-spi2-atk, but Glade does not require a D-Bus environment to run.
Added LibcWrapGenerator.vala

This was salvaged from the old defunct autopackage project, based
on an initial vala port by Jan Niklas Hasse.

This code must be used to generate the libcwrap.h file.
Moved AppRunScript -> AppRun.

The AppImageKit supports a script in place of the AppRun binary.
Committing in tree version of libcwrap.h

This one will work for glibc 2.15, but ideally the libcwrap.h
should be generated on any platform before building with it,
as it needs to be re-generated for any newer versions of glibc.
PrepareAppDir.sh: Copy the AppRun instead of the older AppRunScript.sh
Move build/linux64 -> build/linux

Modified AppRun and jhbuildrc so that the build is 32/64 bit capable.
Improving documentation for bundling.

Added some copyright headers, enhanced the README, added notes
about the sources and their usage in the source headers.