updates for cmake

Remove the "simple SAX" parser. Replace its only use (loading of unit definitions in util/units.cpp) with Glib::Markup

Drop duplicate io code ( Bug #1120585 )

cmake: - group source/headers per library (for some IDE's) - include headers with source listing (also for IDE's) - remove unneeded Find modules

cmake: now builds without having most of the source listed in 1 file.

cmake: turns out my recent commits (which I undid) were not incorrect, variables were set in subdirectories then used in the parent directory, where they were still unset. Fixing this broke the build because some files in the subdir were not compiling.

cmake: give all libs a _LIB suffix, workaround 'debug' being confused with cake keyword, and also dont mix up dor names with libs.

work in progress cmake commit: - cmake now builds all files that automake does but does NOT link yet - inlcudes nasty hard coded paths and libs (will replace once linking works)

Cmake: Fixed the extra -l in the link command, plus a add linking for all sub-libs of inkscape.

Cmake: restructure build files to be more like current build system. Should reduce linking stage command for windows.

Cmake: remove header files from source lists

cmake: copy over some excluded files from build.xml

cmake: EOL of cmakelists.txt in subdirs

add CMakeFiles for io, jabber_whiteboard libavoid libcola.