Added tab_width to linter.py

[remos]

I think tab_width should be specified as the default for more linters.
Is there a reason tab_width isn't specified more often?

Considering that SublimeLinter already parses the reported visual column number to a character column number, it makes sense to me to set the tab_width to the default of the linter itself.
This way, regardless of a person's tab settings the regions should be in the same position. (Only if they change the linter's tab_size setting would it misalign)

Here's an example of it without tab_width where the regions should only be marking the '<'s:

After setting tab_width it works fine.

[aparajita]

Is there a reason tab_width isn't specified more often?

I guess I'm just lazy. Too much sitting around writing software for free so others can benefit and then complain that I don't do enough.

[remos]

I wasn't meaning to complain. I was genuinely curious if there was some reason I hadn't thought of.
SublimeLinter's terrific. I as well as I'm sure everyone who uses it, really appreciates all the time you've put into it.

Cheers.

[aparajita]

I was genuinely curious if there was some reason I hadn't thought of.

I don't use (and didn't write) every linter, and the ones I use are working fine. I just don't have time to go through every linter and figure out what the tab width should be.