Fix for issue#226 "Convert platform to OSGi"

Sorry for the messy commits.  Commit 9de2005 was made, but on reviewing the diff I noticed that there was a large number of lines that showed whitespace differences (obscuring what was actually changed).  Commit 57197d3 reverted the 9de2005 commit, returning the repository to pristine condition.  Commit e4a1158 contains the same changes as the original 9de2005 commit with most of the whitespace differences removed.

As the commit message says:

Build jna-platform jar with OSGi headers. Also, fix OSGi "Bundle-Version" header of core jna.jar to contain full version number, rather than just ${jna.major} number.