encoding names

Hi,

attached is patch with:

- new encoding names stuff with better performance (binary search
intead for() and prevent some needless searching)

- possible is use synonyms for encoding (an example ISO-8859-1,
Latin1, l1)

- implemented is Peter's idea about "encoding names clearing"
(other chars than [A-Za-z0-9] are irrelevan -- 'ISO-8859-1' is
same as 'iso8859_1' or iso-8-8-5-9-1 :-)

- share routines for this between FE and BE (never more define
encoding names separate in FE and BE)

- add prefix PG_ to encoding identificator macros, something like 'ALT'
is pretty dirty in source code, rather use PG_ALT.

(Note: patch add new file mb/encname.c and remove mb/common.c)

Karel

--
Karel Zak <zakkr(at)zf(dot)jcu(dot)cz>
http://home.zf.jcu.cz/~zakkr/

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