Fixed the permissions of the image and source files. Image and source
files should not have their executable-bit set.

Removed the embedded jackon source code and added jackson-core-asl.jar
instead (we use version 1.9.6). Changed the build.xml file to reference
this jar during the compilation process.

Executing the unit tests from the command-line using ant resulted in a
lot of failed tests. To fix this a number of changes had to be made:

- Modified the unit tests containing nested test classes by adding an
  @RunWith(Enclosed.class) annotation at the top.
- Added an @ignore annotation to the HighResolutionTerrainTest2 as this
  test is currently failing. Also, added @ignore annotations for
  IconRetrievalTest and PointGraphicRetrievalTest as these tests take
  too long to execute.
- Made some changes to the run.tests ant-target in test.xml. Firstly, we
  added an option to print the test-summary to give more detailed output
  during test execution. Then, added an exclusion clause for all nested
  test classes ("**/*$*.class"). This ensures that tests are not
  executed twice when using the Enclosed test-runner. Added additional
  exclusion clauses for classes that are not unit-tests.
- Added a clause to test.xml that generates a junit test-report for us.
  The report is stored in HTML format in the testReports directory.