Add Tcl version

[anon00000000]

PR title is explicit
The implementation only count matches, doesn't store them; don't know what it's supposed to do exactly.

Redid PR without CL included, a bit new to the Github PR system.

[anon00000000]

Sample performance (vs Perl):

> tclsh tcl/benchmark.tcl input-text.txt
30.068 - 92
24.901 - 5301
16.300 - 5
> perl perl/benchmark.pl input-text.txt
104.506016 - 92
59.355974 - 5301
19.701958 - 5