Unified Axis Keywords syntax

[VorTechnix]

Axis handling:

For basic operation (and compatibility/consistency with WorldEdit) UAK should take:
[+-]?|x|y|z|h|v,
[+-]f[acing|ront] | b[ack|ehind] | l[eft] | r[ight] | u[p] | d[own],
[+-]0-9...

For Selection Tools UAk should take:
r[ev[erse]] however r by itself should only be recognized as reverse if it is at the end of the axis string and not followed by a number (this way we prevent r[ight] from conflicting with reverse).

r should not be a reverse keyword (on second though).
sym[metrical] | mir[ror] | rev[erse] | true should be the keywords.

Value handling:

In the case of sign overlaps (eg. -x -4) the signs would be multiplied together (so the result would be the same as x 4).

In the case of value overlaps (eg. x 3 x 6) values would be summed with all other values of the same sign on that axes if UAK is working in 2 vector out mode, or with all other values on that axes if UAK is working in single vector out mode.

In cases of orphan values (eg. x 3 5) the orphan value (in this case 5) would be added to all other values of the same sign on all axes if UAK is working in 2 vector out mode, or with all other values on all axis if UAK is working in single vector out mode.

There may be some cases I'm not remembering but this is it for now.

[VorTechnix]

@sbrl What should we do about cases like front 15 noodle 6?

[sbrl]

That should throw an error due to an unrecognised token noodle.