support building/running on all OS X versions >= 10.6

Signed-off-by: Ashish Kulkarni <kulkarni.ashish@gmail.com>
do not pre-create the static-build directory in the build script

This causes problems when the first target is for setting up schroot,
which is typically run via sudo and will ensure that the directory
will be created with root as owner -- fixes #1751
fix compilation of OpenSSL for 64-bit MSVC build

This was due to a copy-paste error in 9db4dce10d8ba81cb854d6994a842b6c9d149726
add target for generating the source tarball in the build script

This includes the complete source code along with the corresponding Qt
source and excludes folders which are not relevant for the compilation
of wkhtmltopdf.
perform the POSIX and OS X builds with -no-rpath

Using `-rpath` can be a security issue as it attempts to load the
libraries from `/home/build/wkhtmltopdf` which is unlikely to be
present on the target machine and can be potentially exploited
by an attacker. This can be mitigated by running `chrpath -d`
on the binaries, but is better to build without rpath -- it also
fixes #1733.
correct API documentation for header/footer spacing (fixes #1708)
correct parsing of ColorMode and PrinterMode in the API (fixes #1757)
add proper support for "make install" and use it for the linux builds
specify explicit dependencies when building the Debian/Ubuntu chroots

A lot of the libraries used by the system Qt4 package are not used by
us, and hence not installing them will save disk space/internet usage
and result in a cleaner build.
Improve docs for --cookie option
specify explicit dependencies when building the CentOS chroots

This is similiar to c8a117ad8c902115b17cc99a710fe1bc3745e98f
upgrade OpenSSL to 1.0.1h to fix multiple security vulnerabilities

Details are at https://www.openssl.org/news/secadv_20140605.txt
fix error on Windows when attempting to remove folders having read-only files
downgrade to libpng-1.5.18 to avoid issues related to the sRGB profile

Some changes in libpng 1.6+ cause it issue warning or even not work
correctly with the original HP/MS sRGB profile. The message you may get
is as follows (originally reported on #1763):

libpng warning: iCCP: Not recognizing known sRGB profile that has been edited

It may result in the profile getting removed, as per
http://sourceforge.net/p/png-mng/mailman/message/32029459/
include missing text codecs to improve support for Asian languages

According to https://qt-project.org/doc/qt-4.8/plugins-howto.html#static-plugins
you need to explicitly link against the text codecs when you are
using a static version of Qt. This will enable support for the
Chinese (Simplified/Traditional), Japanese and Korean languages
and will fix #1764
install the "fpm" and "ronn" ruby gems into the schroot environments

These will be useful for generating distribution-specific binaries
(using fpm) and generating HTML/man pages (using ronn) from Markdown
files created by migrating the existing documentation embedded in
the source code.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	qt
	scripts/build.py