accept a DESTDIR environment variable for libopencm3

differing between ${PREFIX} and ${DESTDIR}/${PREFIX} is important for
creating a debian package, where all hardwired paths have to be set to
${PREFIX}/something, while the actual installation will go to
${DESTDIR}/${PREFIX}/something.
Add zlib1g-dev to apt-get comment

zlib1g-dev is a requirement for Ubuntu 12.04 Desktop 32-bit.
Updated to openocd-0.6.0

Tested on Ubuntu 12.04 Desktop 32-bit.
Add zlib1g-dev to apt-get comment
Added libftdi-dev to apt-get comment
Added git to linux dependencies
Added git to linux dependencies
Merge pull request #29 accept a DESTDIR environment variable for libopencm3

Merge remote-tracking branch 'chrysn/upstream' into beta
Merge pull request #31 Update to openocd-0.6.0 and doc apt-get zlib

Merge remote-tracking branch 'revlon/master' into beta
Merge branch 'master' into beta
Merge branch 'master' into beta

Conflicts:
	README
Updated all tools and libraries to the newest versions. Updated patches.
Removed gengtype patch as it is reversing the fix. Fixes #44
Added variables for wget options. Needs to become a commandline option. Fixes #37
Updated openocd patch and added stlink compile flag. Fixes #38
Corrected the README to reflect the name change of libopenstm32 to libopencm3
Fixed FETCH_NO_CERTCHECK typo.
Updated linaro gcc to 4.7-2013.01
Added a known bug where one has to recompile linaro gcc twice to known bugs in the README.
Updated libcmsis to v1.10-4 fixing a compilation bug.