added missing `sign` argument for apksigner

Closes #1194.

Should be input in hiragana and katakana, not Arabic alphabet.

Language option "stressOpt" already handles separate flags instead of a
single integer. There's no reason to have two ways of setting the same
option.

From now on, stressLength must be set before stressAdd because
stressLength will overwrite any previous value. Usually stressLength is
set in a language file and stressAdd in a voice file.

Previously the order of the two commands didn't matter.

See discussion in #933.

See discussion in #933.

When set in a language file, a period followed by a lower case letter is
detected as end of sentence. Normal behavior is to require a capital
letter.

docs: add details about number flags to the documentation.

It's clearly intended to be enabled by default:
- it's defined as default behaviour translate.h (NUM_DEFAULT)
- tr_languages.c sets many default values related to number processing
  that have no meaning unless langopts.numbers == 1.

It is also a more sensible default since most languages will want to
have number processing on. This makes adding new languages easier
because  adding an entry to tr_languages.c is unnecessary.

A negative side effect is that languages with partial number defines
might experience bugs when reading undefined numbers. This is a bug and
should be fixed.

This will have the side effect of enabling number processing for
languages that currently have it disabled. However, there shouldn't be
any.

Here's a way to check affected languages:
for voice in $(ESPEAK_DATA_PATH=`pwd` LD_LIBRARY_PATH=src:${LD_LIBRARY_PATH}
src/espeak-ng --voices | grep -v Languages | awk '{print $2}'); do
OUTPUT=$(ESPEAK_DATA_PATH=`pwd` LD_LIBRARY_PATH=src:${LD_LIBRARY_PATH}
src/espeak-ng -qx -v $voice "1 - 2 - 3 - 12 - 123") && echo "$voice:
$OUTPUT" ; done

These voices clearly benefit from enabling numbers (they already have
number rules in *_list):
ba, cmn (zh), hak, haw, ja, kok, nb, nci

Some languages are missing some definitions (like _12) in _list files.
It causes the program to skip some numbers.
Numbering needs to be turned off explicitly for:
jbo, mi, my, piqd, py, qu, quc, th, uz

Languages with no number rules at all:
chr, cv, he, nog, tk, ug

using sox for ssml <audio> tag is hardcoded in readclause.c and for
--compile-phonemes in compiledict.c

Currently, --compile-phoneme doesn't need to run sox since the
samplerate for the specific file is correct. There might be a lot of
dead code in compiledata.c

- param2[] is only used to set a second value to LOPT_BRACKET_PAUSE. It is simpler
to have two values in param[] instead. This simplifies the codebase.

- Instead of setting "option bracket X Y" in language files, use
keywords "brackets X" and "bracketsAnnounced Y" instead to follow the
naming convention of other keywords.

- Add missing documentation to docs/voices.md.

See more at: https://github.com/espeak-ng/espeak-ng/pull/863