Use Tycho 0.16 and updated scala versions in POM

* Updated the README build example to use the ``scala-ide-stable``
  profile. Why? Because this is going to make it easier for people to
  start hacking as it is the stable update-site. As a consequence,
  ``eclipse-indigo`` is now used (that the Eclipse version that is
  currently  supported by the 3.0.0 IDE release).

* Removed scala-2.9.x profile because Play 2.1 only supports Scala 2.10
Created a TestSuite class for running all tests in the regression suite

* Updated the POM to run the new ``TestSuite`` class.
Graceful handling of parsing errors from template compiler

Use ``Annotation`` for reporting both parsing and compilation errors from
template files. The implication of this is that compilation  errors are not
persisted and are no longer displayed in the Problem View or the Package
Explorer.

Because we now solely use Annotation, we no longer need the use the Eclipse
extension point for defining new markers (look at the deleted lines in
plugin.xml).

Fixes #29