pgsql: Fix assorted bugs in contrib/unaccent's configuration file parsi

Fix assorted bugs in contrib/unaccent's configuration file parsing.

Make it use t_isspace() to identify whitespace, rather than relying on
sscanf which is known to get it wrong on some platform/locale combinations.
Get rid of fixed-size buffers. Make it actually continue to parse the file
after ignoring a line with untranslatable characters, as was obviously
intended.

The first of these issues is per gripe from J Smith, though not exactly
either of his proposed patches.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/27864da6b1cf9fb3f29dc5abe1eba333cbc4ba77

Modified Files
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contrib/unaccent/unaccent.c | 88 +++++++++++++++++++++++++++++++++----------
1 files changed, 68 insertions(+), 20 deletions(-)