added ++arm:core, +-arm:core, +$arm:core, +*arm:core to udon parser

[jfranklin9000]

Before:

++arm
+-arm
+$arm
+*arm

++arm:core
+-arm:core
+$arm:core
+*arm:core

After:

++arm
+-arm
+$arm
+*arm

++arm:core
+-arm:core
+$arm:core
+*arm:core

This has PR #1091 functionality in it (parsing :core) and can replace it.

Should this be submitted against next instead of master?

[jfranklin9000]

Without this patch

[++abs`:fl`](../library/3b/#--abs-fl-)

from docs/reference/alphabetical-arms.udon displays split:

If this patch is accepted I'll submit a patch to docs that does

[++abs:fl](../library/3b/#--abs-fl-)

It not I'll submit a patch to docs that does

[`++abs:fl`](../library/3b/#--abs-fl-)

[joemfb]

bumping for @pilfer-pandex

[jtobin]

The looks good to me; the example @jfranklin9000 pointed at is now at docs/reference/library.udon, where the splits have since been handled by tics (possibly also contributed by @jfranklin9000 himself). This obviates the need to use tics at all.

[jtobin]

(We're deprecating next and friends, so I've changed the base to master.)

[jtobin]

I'll give @pilfer-pandex a chance to review, but absent any complaints I'll merge this one tomorrow.

[pilfer-pandex]

lgtm