New indenthl syntax plugin

I've still been getting comments on my original indenthl post, lo four or so years ago. Back when I wrote it I was an advocate of the 'set noet' (no expanded tabs - a tab means a tab!) form of consistency. Although I still prefer this method for its individual control (I like 2 char tabs, you like 4 char tabs, some fool likes 8 char tabs) I've noticed at my job people mix spaces and tabs (no we're not a python house, although we were a jython house for a while). The result: UGLY. Anyway, I'm beginning to see some of the virtues of a 'set et' world.

Thus saying, I've done some IndentHL syntax updates. It now has a couple new features (and settings!):

• Error highlighting: if you have a line indented with a combination of tabs and spaces then this will highlight it as an error.
• 'follow the expandtab' setting: If you turn off the expandtab setting then the syntax plugin will highlight anything that isn't TAB'd out as error prone. If you specify et then the syntax plugin will do its same 'indent level highlighting' it did before for spaces (using your shiftwidth setting), and it'll highlight in red anything thats tabbed.
• A setting to turn off error highlighting: maybe you don't care about consistency. Well, you can turn it off.
• I originally designed three different highlight modes (see my original post). You can now pick which one you want (as a setting).

Also, I moved this syntax project over to github. Of course, its over at vim.org as well.