DataSearch paths can disappear on windows

[Nick Draper]

It looks like the paths are written out with \ rather than /

This occured when I altered the data search path in any way and then closed and reopened Mantidplot.

[Martyn Gigg]

To reproduce this:

• Removed all references to datasearch.directories and defaultsave.directory from Mantid.user.properties;
• Started MantidPlot
• Click the Manage data directories button on the toolbar;
• The entries are those from the default Mantid.properties file;
• Type in the same directory as the default save one in to the add directory box at the top of the dialog but with a lower case drive letter;
• Click OK
• Close MantidPlot
• Start MantidPlot
• Click the Manage data directories button on the toolbar;
• All of the entries will have disappeared

[Martyn Gigg]

(In [9538]) Fix problem with saving certain paths after the default save directory had been appended to it. Fixes #2445 Also improve python simple algorithm functions help documentation with a few new lines to make them clearer. Fixes #2459

[Stuart Campbell]

This ticket has been transferred to github issue ​3292