This is a merge of changes from jgralab4android branch to the master
branch. Contains the addition of an explicit class loader parameter for
instantiating schema types. In OSGi context, each bundle has its own
class loader. Loading schemas/models required the explicit passing of a
class loader in this application context. The jgralab4eclipse solution
did not help.

In common.xml, a property was set as a *value* (the relative path of
jgralab: "../jgralab"). This raised some issues on my machine and on
Thomas' Linux machine. Changing it to a location property type fixed the
problem.