Revert "Revert "Upgrade to xtext2.4 (again)""

This reverts commit 5143d0988ac79b32bce9a4dd7db4d395bc66a0ab.
Fix a minor issue with abdera dependency in useragent-examples-simple/pom.xml
One minor change to the comments in hal repository dependencies.
fixes #65 initial implementation of extended odata consumer (for bag / complex type support) that supports getEntities
Organise imports
Merge branch 'master' into xtext2.4-dev

Conflicts:
	interaction-media-hal/pom.xml
	interaction-odata4j-ext/src/main/java/org/odata4j/jersey/consumer/ODataJerseyConsumerExt.java
	useragent-examples/T24-ft-useragent-javascript/.project
Merge commit 'e7c43797ac70969187a30559481836827b085928' into xtext2.4-dev
Merge branch 'master' into xtext2.4-dev
Moved branch on to 0.5.1-SNAPSHOT while we upgrade DS to xtext 2.4.3
Merge commit '00da6b7993baabfda7ecf643e0395d00c8bd77cc' into xtext2.4-dev
Move version of xtext on to 2.5.
Implement the redirect transition '->>' and enable query parameter passing to auto transitions.
Add support for transitions with fully qualified String references to target states.
Merged from xtext dev branch (where we are upgrading xtext version) - this change rolls back the version and xtext dependency version.