REVIEW: [NX-501] Token Pattern Parser

JIRA: https://issues.sonatype.org/browse/NX-501
Bamboo: http://bamboo.s/browse/NX-OSSF255-1
suggest using guava: checkArgument(!disallowed.contains(iterator.current()), "Disallowed character %s at position %s", iterator.current(), iterator.getIndex());