change file/directory structures

* unuse eRuby to generate script (u-aizu/bekobrew#26)
* change xxx.sh -> xxx.bash
* change tmp/bekobrew -> tmp/bekobrew/bekobrew
* change tmp/install.sh -> tmp/installer/install.bash
* change config -> BuildConfig
just use eRuby for version string
Merge branch 'feature/erb' into develop