this is just a memo to keep track of saddleties of plxgettext.

1. xgettext behavior:

it accepts these as escape sequences.

\"    double quote
\t    tab
\n    new line 
\r    return 
\f    form feed
\b    back space
\033  octal sequence.

although it gives warning messages for \r, \f, and \b,
the process goes just fine.  if a back slash appear in any 
other context, it is treated as back slash itself.


2. plxgettext behavior:

it accepts these as escape sequences.

\"    double quote
\t    tab
\n    new line 
\r    return 
\f    form feed
\b    back space
\033  octal sequence.
\a    alarm (bell)
\e    escape
\x1b  hexadecimal sequence
\c[   control sequence
\l    lower case next character
\u    upper case next character
\L    lower case until \E
\U    upper case until \E
\E    end of case change
\Q    quote regexp meta characters till \E

plxgettext also warns \r, \f, and \b, and processes them.
\a, \e, and control sequence will generate warnings, but 
get processed.  hexadecimal sequence are processed silently.
\l, \u, \L, \U, \E, and \Q are perl special sequences
used for pattern maching.  therfore, they will be left
with the back slash (no translating).  if back slash
appears in any other context, it is discarded, so the next
character is treated as is.  this includes @ and $ sign,
which would normaly be interpreted by perl if in double
quote string.  the list below summerizes this.

\t \n \033 \x1b
   translated into appropriate character silently

\r \f \b \a \e \c[
   translated into appropriate character with warning

\l \u \L \U \E \Q
   left with back slash

\\ \" \@ \$ and all other characters preceded by a \
   back slash removed.  double quote loses special meaning.
   \\ will leave one literal back slash.
