Current legacy parser

[strato-cumulus]

This exposes two different versions of uap-core through uap-java. Some notes about the changes:

• CurrentParser and LegacyParser have been extracted as distinct classes because I wanted to abstract out dealing with the underlying regex file, There has also been one code change in the equals method of UserAgent in the parent repo accommodating for newer versions of the regex list - there's a switch which turns it on in CurrentParser to ensure maximum compatibility.
• I verified that CachingParser is not used in dmp, so I did not split it out, making only a minimal code change so that it points to the newer version.

[diogoaurelio]

@strato-cumulus : sorry, I think I am missing the big picture here. My doubts are:

• why do we need to bring to uap-java lib the concept of Legacy and Currency? Aren't these terms that only make sense in the context of DMP?
• afaiu, there are only 2 differences: regex file being used and a minor fork in the implementation of "UserAgentParser", which varies in its match method; the regex file we can inject from the outside (in dmp when we instantiate the parser), right?; the UserAgentParser change is trying to affect when to mutate fileds v2 and v3, by assuring that we only assign either null or values that are different than empty string; besides seemingly a microscopic change, am wondering if we couldn't just rather make the UAPattern class public, and optionally inject the class in UserAgentParser? This would save us the need to inject in this library concepts from the DMP.