Support for basic asciidoc table

[thawk]

The basic simplest asciidoc table is like the following:

[cols="2*"]
|=== 
| Cell in column 1, row 1 | Cell in column 2, row 1  
| Cell in column 1, row 2 | Cell in column 2, row 2
| Cell in column 1, row 3 | Cell in column 2, row 3
|=== 

The basic and simplest roles are:

1. The table’s content boundaries are defined by a vertical bar followed by three equal signs (|===).
2. The new cell is marked by a vertical bar (|).
3. Rows can optionally be separated by any number of blank lines.

Table-mode is working for table cells, but it adds a space between | and ===. Is there any setting to prevent this? If not, I suggest that we should support the basic asciidoc table.