GPR grammar tests in progress.
Merge branch 'master' of git@github.com:cdonnat/padacore.git

Conflicts:
	org.padacore.core.test/src/org/padacore/core/gnat/test/GprGrammarTest.java
	org.padacore.core/src/org/padacore/core/gnat/Gpr.g
	org.padacore.core/src/org/padacore/core/gnat/GprLoader.java
	
Fixed AdaProjectPropertyTester test.
Added tests for GPR grammar.
Added tests for GPR grammar.