Fix issue #6 and #10 (#12)

* Fixed issues #6 and #7, fixed javadoc error in pom.xml.

* Changed package name to com.teragrep.jpr_01 from com.teragrep, added public modifiers to name_table and match_table.

* Added pcre2_get_name_table() and pcre2_get_match_table(), added testcase for added functions.

* Changed JavaPcre.java ovector0, ovector1, pattern_size and pattern fields to private.

* changed offset field to private and added get/set functions for it.

* Changed matchfound field to private and added get_matchfound().

* Changed JPCRE2_ERROR_NOMATCH field to private and added get_JPCRE2_ERROR_NOMATCH().

* Changed re to private and added get_re().

* Changed gcontext, ccontect and mcontext to private, added corresponding get-functions.

* Changed option struct fields to private and added corresponding get-functions. Removed "pcre2_" from all function names for better clarity.

Author: Tiihott