WIP/RFC: add locale folder for helpdb.jl

[wlbksy]

If sys.ji in #2498 can be alted,
this pull would create a help folder in $(BUILD)/share/julia/help/
and LOCALE for base/util.jl to eval specific helpdb_what_ever_lang.jl

[pao]

Newline, please.

[pao]

One issue that's immediately clear is that the Travis builders can't produce helpdb.jl.

[wlbksy]

haven't figured it out . Please do not merge,

[pao]

You'll need to modify the .travis.yml file I think.

We'll also need to rework the patchset in any case, so don't worry about it. I'm going to retitle to note the status.

[ViralBShah]

Does this mean that we can have all the translations in one place?

[wlbksy]

I'm trying to put them in one folder. But someone gonna make sure that helpdb.jl would not be hard coded in sys.ji

[wlbksy]

Providing helpdb.jl would not be hard coded in sys.ji in the future,
i18n would be done as follows, take Simplified Chinese for example :

1. Put your specific helpdb file helpdb_zh_CN.jl into $JULIA_HOME/../share/julia/help/
2. Modify the last uncomment string at the end of $JULIA_HOME/../share/julia/help/LOCALE into "zh_CN"
3. Restart REPL, test help()

[ViralBShah]

We probably want those commits squashed before this can go in.

[JeffBezanson]

It's very easy to change the way helpdb is loaded, and we will certainly do it to get i18n.

[JeffBezanson]

Would it make sense for this to use the locale environment variables?

[wlbksy]

I myself find locale environment variable hard to use, I think that part is beyond my knowledge at present.

Besides, I believe there would be some people like to change helpdb's language freely. Inevitably, all translations would be slightly different from original version. There would be in some cases, people would like to see to English version.