strip lists and extend webdocs

[jakobkogler]

.s (strip) works now also with lists. E.g. .s[0 0 1 0 2 0)0 => [1, 0, 2] Docs and tests included

Added the various string operations ra0-9 and the trigonometric functions to the web-docs. (nobody uses doc.txt anymore)

[jakobkogler]

Also implemented a Pad-operator. E.g. .["hallo"\.8 => hallo..., .[N3\a => "a" or .[Z5U3 => [0, 0, 0, 1, 2].

The order of parameter determines, if the padding happens on the left site, on the right site or on both sites. If this is too confusing, we could also split the operator .].[.???.

Docs and tests included.

[refi64]

+1 for the pad operator. That has bitten me a few times in code golf.

[orlp]

Hey, I use doc.txt!