Load latexsub table as a feature

[non-Jedi]

Fixes #91. Alternative to #92.

Variable renamed from julia-latexsubs to julia-mode-latexsubs as incremental improvement towards melpa guidelines.

[tpapp]

I think this may be the cleanest solution, favoring this over #92.

[tpapp]

My preliminary exploration suggests that this should work fine with

1. MELPA, simply including all the .el files like now, without an extra recipe,

2. the Emacs package loading mechanism, which puts package directories in load-path so it should always fine the relevant file.

I will keep testing this, comments and reviews are welcome.

[nverno]

@non-Jedi If you are still considering going the abbrev route for latex substitutions, I forgot to mention I have been doing similar in my personal configs, although I believe the generating script to produce the abbrev table from the unicode generating script is out-of-date.

If your interested, the relevant script to generate the abbrev table is at latex_abbrevs.jl which should produce a unicode-latex-abbrev-table.

I'm also a bit obsessive about abbrevs, so there are lot of various abbrev hacks in there. A really nice feature that comes with have a unicode latex substitution table, is the ability to use it in any other mode. The method I found the most useful and least intrusive (only minimally effecting the other active abbrev tables by giving them precedence, and being easily disable/enabled on the fly) was have an interactive function to add an additional abbrev table to the current buffer by adding it as the parent of the local-abbrev-table. Adding the unicode expansions on the fly is nice if you know when they'll be useful or annoying. This is the function I'm referring, and is quite simple. Sadly, I have a couple personal functions worked in there that could be annoying to deal with.

One think I always found annoying was when modes defined abbrev tables without customizable options in mode hooks. This seems to have fallen out of fashion recently though.

[tpapp]

neat work, thanks!