Pyarmor

* Add platform data file `index.json` to source package
* Refine core library for platform MacOSX

* Fix issue: advanced mode doesn't work in some MacOSX machines.
* Fix issue: can't get the serial number of SSD harddisk in MacOSX platform

* Fix issue: the `_pytransform.dll` for windows.x86_64 is not latest

* Fix issue: the option `--exclude` in command `obfuscate` could not exclude `.py` files
* Refine command `pack`

* Fix issue: check license failed if there is no environment variable `HOME` in linux platform
* Add new value `3` for option `--package-runtime`, the bootstrap code will always use relative import with an extra leading dot
* The command `runtime` also generates bootstrap script `pytransform_bootstrap.py`
* Add option `--inside` in command `runtime` to generate bootstrap package `pytransform_bootstrap`
* Document how to run unittest of obfuscated scripts, refer to
https://pyarmor.readthedocs.io/en/latest/advanced.html#run-unittest-of-obfuscated-scripts

* Move the license file of pyarmor from the install path of pyarmor package to user home path `~/.pyarmor`
* Refine error messages so that the users could solve most of problems by the hints.
* Refine command `pack`, use hook `hook-pytransform.py` to add the runtime files.
* The command `pack` supports customized spec file, refer to
https://pyarmor.readthedocs.io/en/latest/advanced.html#bundle-obfuscated-scripts-with-customized-spec-file
* In runtime module `pytransform`, the functions may raise `Exception` instead of `PytransformError` in some cases.
* In command `register`, add option `--legency` to store `license.lic` in the traditional way
* Fix platform name issue: in some linux platforms the platform name may not be right