Make slices in the table notation "international"

Currently, names of slices can only consist of latin letters without spaces: [\.\w]+

This is somewhat inconvenient, sometimes one needs to make and then aggregate slices with names, say, in cyrillics.

For more details about the proposed slicesRe see [1];
here, other space symbols are also forbidden: \f, \r, \t
(not sure about the first two, this is to avoid confusion with \n, but they can be permitted if needed;
the \t is for another novelty - the \t* part after \:? allows to align slice tables visually in the edit mode, see below).

|name		|value|
|anotherName	|anotherValue|

[1] https://groups.google.com/forum/?hl=en.&fromgroups=#!topic/tiddlywikidev/yFNObuerUw8