Rather than adding to the saveas dropdown I changed it to a simple
string that gets parsed. The help was upgraded in the process.

1. Refactored and thus fixed some issues;
2. Added  more unit tests;
3. Change input property. Algorithm can work with 1 spectrum only.

Couple of things to note:
 - The CreateOutput option defaults to false so the algorithm won't
suddenly start churning out lots of workspaces.
 - As the algorithm outputs all the parameters to a single table,
regardless of the number of input workspaces, I've chosen to output all the
output workspaces to a single group per type.
 - Output workspaces are numbered according to the spectrum in the input workspace
used.

and though it can be compiled in some convoluted way, (and probably did on Jenkins) it is much better to have it declared.

Refs #8784

Refs #8784

Looks like this is due to lack of language support against 2.7.

Instead of passing the resulting monitor from SliceEvent to
NormalizeToMonitor, just use a scaled version of the same monitor that was
passed to SliceEvent.

These changes should also make the process of having monitors in a
different time regime easier, which is an issue we will be facing in the
future.