Fix NPE when deleting the first statement
Added ActionPrint, AssignString and AssignReplace classes
Issue 44: Fix expressions to work on just requests where relevant
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/org/mozilla/zest/core/v1/ZestExpressionEquals.java
	src/org/mozilla/zest/core/v1/ZestExpressionRegex.java