Enforce spec version requirements for more install properties

[HebaruSan]

Background

The spec says:

https://github.com/KSP-CKAN/CKAN/blob/master/Spec.md#install

• filter_regexp : (v1.10) A string, or list of strings, which are treated as case-sensitive C# regular expressions which are matched against the full paths from the installing zip-file. If a file matches the regular expression, it is not installed.
• include_only : (v1.24) A string, or list of strings, of file parts that should be installed. These are treated as literal things which must match a file name or directory. Examples of this may be Settings.cfg, or Plugin. These are considered case-insensitive.
• include_only_regexp : (v1.24) A string, or list of strings, which are treated as case-sensitive C# regular expressions which are matched against the full paths from the installing zip-file. If a file matches the regular expression, it is installed.

The version numbers in parentheses are supposed to be the minimum spec_version required to use the given property.

Problem

Currently you can use these properties with any spec_version and Netkan will not complain. This means that a client supporting an old spec version might be presented with metadata that it can't handle (but this is very unlikely to ever be a real problem because there is really only the one client, and versions of it that old won't even run anymore thanks to TLS changes on GitHub).

Changes

Now Netkan's InstallValidator enforces these requirements.

[techman83]

This seems sensible to me, a founding principle of the project has been ensuring we produce consistent metadata.