Inclusion of the source files from tpp/mzParser.

Files saxhandler.cpp, saxmzmlhandler.cpp and saxmzxmlhandler.cpp
from rTANDEM are replaced by their equivalent from tpp/mzParser.
.hpp files were created a warning.
They have been renamed and #includes have been modified accordingly.
Instead of replacing xtandem files by the corresponding files in mzParser,
the content of the mzParser files has been added to the xtandem files.
Flags for compiling mzParser has been added to the Makevars.
Some functions from this file duplicate the functions from base64.
They are commented out.
Added link to the zlib library in linux.
Added dependency on zlibbioc for zlib support on Windows (followed the
instructions from the zlibbioc vignette).
New files from xtandem tpp to use mzParser
Added the intercept function to redirect parsing to mzParser
Removed the inclusion of the code from ramp parser.
An attempt to use ramp parser will produce an error message.
Modifications for compilation on windows with zlibbioc
Version update to 1.5.1