re #15286

...and replace external calls to it with ones to the method that returns
the cached result - getNumElements(). Re #4051.

Refs #3244: LoadEventPreNexus parallelized. Loading NOM_640 took 143 seconds (release mode) before, now takes about 46 seconds (for a 4 GB file). 

Refs #3157 Sort our System.h. It was becoming a dumping ground. It should only be touched when absolutely necessary as it affects every file in Mantid. Also combined this with Refs #2345 to sort out DLLExport/DLLImport usage. It's done for Kernel, Geometry and API but stuff in the plugins could do with updating as well.

Fix the BinaryFileTest on windows. The dummy file was trying to be deleted while the file handle was still open. Windows locks access to files while any handle is open which resulted in a file access error. Refs #2191  

Rename Framework code directory to just that. Also delete Main and VS & Eclipse project file. Re #1881.

Refs #1396: Successfully parallelized the loadEventPreNexus algorithm; however, it only runs 10-15% faster, and that only on large files and with the right settings. Therefore I have disabled the parallelized loading option in this checkin, so that it does not clutter the UI needlessly.

Refs #1480: Simplified LoadEventPreNexus to use BinaryFile functionality; fixed a test under windows; commented out a test that fails for reasons unknown...

Refs #1480: added a BinaryFile template class to make loading simple binary files easier with more code reuse.