Re #10608. texlive adjustments for rhel6.
re #10549 create DownloadFile and InternetHelper
Squash warnings on gcc.

Refs #10549
Allow a WorkspaceGroup of 1 item

Refs #10621
re #10549 merge master and resolve conflict
re #10549 resolve linux error
re #10549 mac only error
re #10549 Fix warning
Merge remote-tracking branch 'origin/feature/10549_Internet_Service'
Merge remote-tracking branch 'origin/feature/10621_elasticwindowmultiple_use_single_matrixworkspace'
Merge pull request #72 from mantidproject/feature/10608_rhel6_rpm

Fix rpm dependencies on RHEL6
Merge branch 'master' into feature/10626_better_preview_plots_in_indirect_ui

Refs #10626