Import fixes

Use IJ log file if insight is run as a plug-in.

To test:
 * run ```./build.py release-clients``` to generate the ```insight.ij``` jar.
 * Drop it and unzip it in the plugins folder of image J.
 * Start imageJ.
 * open the insight log file ```omeroinsight.log```
 * Open the OMERO plugin. Connect. 
 * Check that nothing is added to  ```omeroinsight.log```