Update CHANGELOG.md

Merge pull request numenta#516 from cogmission/release-0.6.12

Update build files for new release

Merge pull request numenta#503 from cogmission/gradle_build_fix

Gradle build fix

Update README.md

Merge pull request numenta#484 from cogmission/potential_radius_fix

Added fix for potential radius

Merge pull request numenta#419 from cogmission/slight_persistence_patch

Slight persistence patch and HTMObjectIn/Output constructor change.

Merge pull request numenta#414 from cogmission/update_build_4newrelease

Update build files for new release

Merge pull request numenta#357 from cogmission/v0.6.5-alpha-prep

prep for new version

Merge pull request numenta#335 from cogmission/prep_v0.6.3

Prep v0.6.3

Merge pull request numenta#313 from cogmission/0.6.3-SNAPSHOT

0.6.3 snapshot