Improve "init" command

[ivankravets]

From pull #29 @bettabacon

This was quite messy though. It installed a ./lib, ./src, and platformio.ini without asking me where. I'll move these directories and setup file elsewhere, and try to get

platformio init command initialises empty project within the current folder where you are stayed. See details here http://docs.platformio.ikravets.com/en/latest/userguide/cmd_init.html

Do you have any propositions how to improve the behaviour of this command? I have the next propositions:

1. Add additional option to this command platformio init -d %path_to_project_dir%
2. When that option is not specified, then show a warning message that PlatformIO is going to create ./lib, ./src and platformio.ini in the current "shell" directory.

[ivankravets]

@bettabacon, More details: http://docs.platformio.ikravets.com/en/latest/userguide/cmd_init.html

[ivankravets]

Please run platformio upgrade
https://twitter.com/platformiotool/status/539533696404299776