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

* Because the Play template compiler throws an exception as soon as a parsing error is
encountered, calls to the Play template compiler are now wrapped in a ``Try``.
It's the responsability of the calling code to handle the failure case as it
makes sense.

* Use ``Annotation`` for reporting both parsing and compilation errors from
template files. The implication of this is that compilation  errors are no longer
displayed in the Problem View or the Package Explorer.

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

* Finally, I'm aware that the code could use some more clean-up, but my intention
was to minimize changes as we plan to release 0.1 possibly next week already.

Fixes #29
Merge pull request #54 from dotta/issue/catch-errors-from-template-compiler-29

Issue/catch errors from template compiler 29
Don't restrict where templates can be located..

.. but log a warning in the Error Log (in case this proves a bad idea).

Fixed #45.