fixed request tests
OPEN - task 13: Implementation of the upload properties 
http://github.com/th-schwarz/C5Connector.Java/issues/issue/13

- fixed FileUtils#isImage: position wasn't reset
- simplify the handling if image extensions
docu
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docu
docu
Merge branch 'master' of https://github.com/th-schwarz/C5Connector.Java.git