typekit.rb: aaaand finally switch to clang

http://www.jwz.org/images/theclapgy0wl5.gif

- added additional option 'include_paths' for clang-based importer. This
  is needed, so that the importer tool can be called with the correct
  include paths set. maybe there is a way around this?

- remove "EIGEN_DONT_VECTORIZE" flag for clang-importer. clang does not
  seem to need this? at least everything still builds. has to be
  runtime-validated, for sure. but should reduce complexity.

- replace "gccxml" with "clang" for preprocessing as well. the output of
  the preprocessing is needed by orogen to resolve the "orogen_include"
  metadata... the preprocessed output is additionally later given to the
  importer with the intend to save overhead... but it cannot be used
  without denying some of the clang-features like doc-string, base-classes
  or source_file_line.

also adopt minor stuff on the way -- prints and naming-schema of the
Tempfiles for example.

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>
typekit: source_file_line: convert included files from preposser into absolute filenames

hmhm... thus might be discussed... see corresponding comments in the importer

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>