adding support AsciiDoc context for live templates

I prepared a first draft to support AsciiDoc language context within Live Templates. 

Using this, you can restrict your favourite live template to only AsciiDoc files. 

![adlivetemplate](https://cloud.githubusercontent.com/assets/3957921/5458617/1c4ff8a4-8554-11e4-9847-39e25e46c8d9.PNG)

I want to supply some default templates with the plugin - any suggestions? A starter would could be a two-column table with a heading (but I know that table wizard is underway). 

Suggestion for `tbl2` = "Two Column Table" template:

    |===
    | $cell1header$ | $cell2header$
    
    | $cell1row1$ | $cell2row1$
    | $cell1row2$ | $cell2row2$
    |===

Please paste your favourite template here so we can supply some standard templates.