dump file may be unreadable by bufr_encoder when LC_ALL is defined

[vanh souvanlasy]

When internationalisation is in use, i.e. defining LC_ALL to other language than english. The dump file will
contains printed values that are also internationalized, i.e. all fractions are formatted differently.
For example, in english 1.234 but in french, it would be 1,234, etc...
Currently, the character "," is used as a delimiter in the parser, with some modifications, it is possible to read back
printed string if LC_ALL is defined to use the same language.
However that will still break the encoder if dump file were not created in the same language as the encoder,
and this will make things really complicated.

[vanh souvanlasy (vanh-souvanlasy)]

Solution is to force all dump file to be created in english only and to force re-encoding in english also.
Changes were done throught bufr_decoder.c and bufr_encoder.c by setting LC_ALL=en_US before enabling internationalisation.
commited to trunk rev.149 and to branch 0.8.2 rev.108