pgsql: Fix copyright notices, other minor editing in new range-types co

Fix copyright notices, other minor editing in new range-types code.

No functional changes in this commit (except I could not resist the
temptation to re-word a couple of error messages). This is just manual
cleanup after pgindent to make the code look reasonably like other PG
code, in preparation for more detailed code review to come.

Branch
------
master

Details
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http://git.postgresql.org/pg/commitdiff/f1585362856d4da17113ba2e4ba46cf83cba0cf2

Modified Files
--------------
src/backend/catalog/pg_range.c | 14 ++--
src/backend/utils/adt/rangetypes.c | 142 +++++++++++------------------
src/backend/utils/adt/rangetypes_gist.c | 85 +++++++++---------
src/include/catalog/pg_range.h | 23 +++---
src/include/utils/rangetypes.h | 117 ++++++++++++-------------
src/test/regress/expected/rangetypes.out | 2 +-
6 files changed, 172 insertions(+), 211 deletions(-)