Added fields injection for the delegate instance loaded when handling signals

The delegate instance used when handling a signal could be different than the one used when the execution has been handled (like a new instance), so there is the need to re-inject fields expressions otherwise they could be not accessible by the instance handling the signal
Added optional import of packages from bundle activiti-camel in the manifest of the bundle activiti-engine.
Check thread in forum (http://forums.activiti.org/content/activiti-camel-osgi-problem-imported-packages) for details on the problem
marked process property in lane as backreference, to avoid endless recursion and heap space error when marshalling json-model
ACT-1600: saving namespace from process
ACT-1795: corrected example linechart in userguide
ACT-1625: not warning found DI for artifacts (textannotation, assoc)
Merge pull request #131 from lukakama/patch-1

Added fields injection for the delegate instance loaded when handling si...
Merge pull request #141 from gtudan/ACT-1801

ACT-1801: fix JSON-Serialisation of process with lanes
Merge pull request #136 from ojdiez/master

OSGi: optional import-package in activiti-engine for the packages of activiti-camel
ACT-1780: corrected REST user create/update docs
Fixed ACT-1773
ACT-1777: non-null timestamps are best initialized with default on mysql
ACT-1728: subprocess startActivityId and start-event recored in history
ACT-1698 encoding fix

ACT-1698 Activiti fails to build when default charset is Windows-1252
http://jira.codehaus.org/browse/ACT-1698
Merge pull request #144 from martin-grofcik/SMALL-issues

ACT-1698 encoding fix
[merge] from Activiti