add dialog resetting
add experiment export script

Experiments data can now be exported from the command line.

* Export experiment annotations
* Export experiment images
* Export experiment info
* Export experiment data
* Export README.txt with bam data
add support for experiment downloads
fix removes download callback from dialog
add file cache and completion check
refactored exporting

Experiments now use the export script to perform exporting.

* Added additional annotation and info metadata
* Export file generated using export script
* Moved low level code to export script