update uima-wide parent-pom

Additional updates beyond UIMA-5856.  Remove redundant/outdated versioning now provided by current apache-wide parent-pom (21). add common configuration for api change report.

Attempts to use the checksum-maven-plugin reveal that it doesn't work correctly, see https://github.com/nicoulaj/checksum-maven-plugin/issues/63 ).  Design a work-around that uses Ant scripts, and insure it works both for maven-deploy targets (e.g. .m2) and for normal apache distribution targets (e.g. project/target ).

Due to bug in the current implementation of the maven-gpg-plugin ( MGPG-66 ), the gpg plugin needs to be run before doing the .sha512 checksumming (otherwise the checksums also get signed).