v1.21.7

-- Step 5 of changing the way Homer3 stores the group data in memory, how it saves processed data and loads processed and acquired data. Implemented loading and freeing of acquired data.

-- Removed old code to quickly calculate memory required and check for enough disk space. The rationale for getting rid of this code is that I'm not sure this is a big problem people are encountering and woth complicating already intricate code which we want to keep as simple as possible. The distributed storage scheme should take care of the issue of limited max size of a single file (groupResults.mat). If running out of disk space proves a widespread issue we can re-introduce that code.

-- Returned original slow-running implementation of MemoryRequired for diagnostic purposes but not meant to be run during a user session of Homer3.

-- Change MainGUI.GetWl.m to get selected wavelength ONLY from GUI