Fix a nasty bug in JavaHL's mergeinfo parser; it would parse a single
revision R in a range list into a range [R,R] instead of [R-1,R], which
later triggered an abort in libsvn_subr/mergeinfo.c.

[in subversion/bindings/javahl]
* src/org/apache/subversion/javahl/types/RevisionRange.java
  (RevisionRange.RevisionRange): When parsing a string representation,
   convert a single revision "R" to a range [R-1,R], not to [R,R].
  (RevisionRange.toString): Collapse [R-1,R] ranges back to "R".


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1563140 13f79535-47bb-0310-9956-ffa450edef68