issue #1003: added feature to use backslash escaping for CSV data in arangoimp
updated documentation
Fix escaping of asterisks in AQL documentation.

Asterisks need to be escaped with backslashes, but if surrounded by square brackets, the brackets need to be escaped as well. Does not apply to parentheses it seems, but maybe other characters with special markdown meaning.
issue #1007: fixed broken markup
further documentation fixes, provided by @CoDEmanX
Merge branch 'devel' of https://github.com/CoDEmanX/ArangoDB into CoDEmanX-devel

Conflicts:
	Documentation/Books/Users/Aql/Advanced.mdpp
	Documentation/Books/Users/Aql/Functions.mdpp
	Documentation/Books/Users/Aql/GraphOperations.mdpp
	Documentation/Books/Users/AqlExamples/Grouping.mdpp
Merge branch 'CoDEmanX-devel' into devel
Merge branch 'devel' of https://github.com/triAGENS/ArangoDB into aql2