Refactor build system, simplify templates and escape macros in code

Refactor build system into several modules:
- `settings.py`: to provide common settings (from `buildsettings.py` / `localbuildsettings.py`)
- `build_plugin.py`: to build single plugin
  formats userscript metablock, preprocesses sources - makes templates substitutions,
  inlines dependencies js/css/img - and wraps into wrapper (from `pluginwrapper.py`)
- `build_mobile.py`: to build android apk (embedding scripts from given directory)
- `build.py`: to build all: main IITC script, all plugins, and (optionally) Android apk.

Each module can be used independently as cli utility.

Escape macros in code in order to keep js-validity, fix IITC-CE#50.
Simplify userscripts source template, completely get rid of these ugly substitutions:
- `@@MetaInfo@@`
- `@@PLUGINSTART@@`
- `@@PLUGINEND@@`
- `.@@DATETIMEVERSION@@`
- `[@@Buildname@@-@@BUILDDATE@@]`

Rename plugin sources:  `*.user.js` -> `*.js`

Close IITC-CE#150: use template from settings instead of url harcoding.

Close IITC-CE#99: remove timestamp component from `version` of Release scripts.

.travis.yml

@@ -39,9 +39,8 @@ before_script:
 - ssh-add /tmp/deploy_rsa
 
 script:
-- wget https://iitc.modos189.ru/deploy/$BUILD_TYPE/localbuildsettings.py
+- wget https://iitc.modos189.ru/deploy/localbuildsettings.py
 - ./build.py $BUILD_TYPE
-- ./build.py mobile
 
 deploy:
   provider: releases