Enable LoadMask to support ISIS mask file format

[Wenduo Zhou]

ISIS uses another format for mask file other than XML format. LoadMask is required to support this type of mask file too.

The format of this type of mask file is described in method "load_mask" of /Code/Mantid/scripts/Inelastic/CommonFunctions.py.

Here is the definition of the format of this type of masking file.

1. There are two types of unit presentation for spectrum or spectra list
   • a : a single spectrum with ID a
   • a-b / a - b / a- b / a- b: a list of spectra with IDs ranging from a to b. (a <= b)
2. Each line can contain one or more than one unit described above. Two adjacent ones will be separated by space or spaces;
3. File contains one or multiple line.
4. No tab is allowed.
5. Comment line is supported. The first none space character of a comment line CANNOT be a digit.

[Wenduo Zhou]

Add support of ISIS format. Refs #4832.

No unit test added so far.

Changeset: 755c5c760f00860db15a8f803a7b96a63a556e53

[Wenduo Zhou]

Add unit test and fixed bug. Refs #4832.

Changeset: af173edddfaf4bc5bad6619835ffa97d16f97036

[Wenduo Zhou]

Try to fix failure on build server. Refs #4832.

Changeset: 21ed4c82edb4e636b6ea06116a3209c5d5f46d16

[Stuart Campbell]

This ticket has been transferred to github issue ​5679