Hardcoded full paths in different tools

[Seramis]

There are some utilities that contain full path to devkit's default installation directory. That renders it impossible to install devkit into any other place than default path.

Example: Espressif/utils/gen_appbin.py:123
Because of that, compiling fails as it is unable to eventually create eagle.app.flash.bin file into project's folder.

[CHERTS]

You can change the way files gen_appbin.py and others and compile a new executable files (* .exe), but you need to install Python 2.7