generate consistent module + package structure

[nadako]

ts2hx should generate a consistent and useful package/module structure similar to what's implemented in hxnodejs (and discussed in HaxeFoundation/hxnodejs#16 before).

basically that means the following:

• a module becomes static class with capitalized name (and underscore changed to CamelCase)
• types defined in the module go into a subpackage named after the original module

for example, node's "fs" module become Fs.hx, and "fs.Stats" goes to fs/Stats.hx

[Simn]

ping @ousado

[nadako]

ping @frabbit too i guess

[frabbit]

i like the nodejs structure and your suggestion sounds good.