Move BoostIO templated code into the libraries

This does not fix the BoostIO, but is the first step:
  * CondFormats fully compiles with serialization code in-library.
  * Most of CondCore (including the CondDBImport.cc) compiles.
  * testSerialization* trivial tests run succesfully.
  * Now we do not need the increased -ftemplate-depth option
    (however we keep -O0 for the moment).

Some of the missing bits:
  * Reimplement the equal() feature.
  * Mark the polymorphic types as we discover them
    (i.e. they will fail when importing real objects).
  * Fix any other serialization dependencies/callers
    and their BuildFiles.