* refactor: move `irep_remove_lv` from `mruby-bin-strip` gem to src/dump and rename to `mrb_irep_remove_lv`
* add: mrbc option `--remove-lv` to remove LVAR section

Added ~/Android/Sdk/ndk-bundle as default NDK home

Support MRB_WITHOUT_FLOAT to mruby-io

Add information about Kernel#binding

Run tests parallelly for each target.

Increase sleep duration exponentially instead of `Thread.pass`.

Use Fiber#transfer instead in minirake.

Use `Thread.pass` instead of sleeping.

Fix job waiter of minirake.

Show minirake backtrace in verbose mode.

Use temporary file name for `File#mtime` test to avoid conflicts.

Make minirake parallel.

Fix build scripts.

Fix memory leaks in mirb.

This will improve the default performance of mruby; fix #4045