tomcat: create tap for SSL, APR, gzip & MySQL

This tap is an extension of the work I did on https://github.com/Homebrew/homebrew/pull/24049
Ultimately, the homebrew maintainers felt that adding options for SSL, APR and gzip were not appropriate for the master tomcat formula.
So I'm creating a tap for those who wish to use these features.

Added option to configure tomcat for SSL (https support) using self signed certs. If building with APR, generate a cert using OpenSSL, otherwise generate a cert using java's keytool.
Added option to set up Apache Portable Runtime (depends on tomcat-native)
Added option to configure gzip compression when serving compressable mime types
Added option to install the MySQL JDBC connector in tomcat's lib folder to support container managed MySQL connection pools
Verified all above functionality on tomcat 8 (when --devel is specified)