Add support for operation templates

[Rich Harkins]

It would be really handy to be able to define a operation type of some name with the same ending paramaters so that it doesn't need repeated over and over again. This would be particularly useful for tf.select, which could be reused over and over:

{{{
#!TracForm
#! operation vote select 3//High 2//Medium 1//Low

|| [tf.vote:choice1] || Choice 1 ||
|| [tf.vote:choice2] || Choice 2 ||
|| [tf.vote:choice3] || Choice 3 ||

}}}

[Rich Harkins]

Supported in r3904.

[Rich Harkins]

Actually also in r3903.