ENH: restructuring and new functionality for TCIA summary reporting

* reorganize the code to keep TCIAClient in a separate library to facilitate reuse outside Slicer
* added script to query all available series and save in a file for subsequent analysis
ENH: include additional attributes to be reported
BUG: remove missed merge conflict annotations
BUG: fix instantiation of TCIAClient
Merge pull request #19 from fedorov/stats-script

Code reorganization and TCIA summary script
ENH: caching results to files added
ENH: added access time to group box titles
ENH: Functionalit for use cache ceckbox added
STYLE: removed patient table checkstate and hide reload button
ENH: context menu for integrating clinical data from tcga added
Fix: fix the crash in getting clinical data and some code refactoring for clinical data popup class
ENH: added icon Patient IDs with clinical data
ENH: Added icons to the clinical data popup and also TCIA browser
Merge pull request #21 from QIICR/20-integrate-clinical-data-from-tcga

20 integrate clinical data from tcga
ENH: reorganize the code and put the APISettingsPopup and ClinicalDataPopup into TCIABrowserLib
STYLE: removed old unused settings part
ENH: Moved the storage path directory button from browser popup widget to module settings collapsible button
ENH: Replaced download buttons with icons and some other ui changes
STYLE: hide the reload button
FIX: fix an issue in clinical data cache update