Add record_seconds, record_ms and record_samples variables done recording.
original patch not used due to refactor in code.

Bad things must have been happening when this was hit.

This was introduced in commit 5cb4cd9d

FS-5148 gsmopen: wait for the first audio write() before giving the AT command that moves the audio path to the audio tty (eg: don't accumulate noise by not sending frames on the open tty)

gsmopen: on Linux, automatically find out and setup audio and data ports associated to dongle model, IMEI and IMSI

FS-5568 --resolve the real problem is that L=-1 is not valid because the L param is about how many times to generate the output while generating the tone so -1 is impossible because it can never end to let you hear it.  The real fix is to not allow -1 loops=-1 is the correct way to do this because that is parsed after the tone is generated and repeats the entire thing.  Doing something like L=100 actually generates the whole slinear audio 100 times into memore where loops=100 only generates the little snippet and repeats it after it was generated.

When you use $12345 in regex substitutions, it isn't obvious
whenever you mean $1-concatenated-2345 or $12-concatenated-345
or any other variation.  In all other languages, in order to
solve this ambiguity, a braces {} are allowed to be used to
separate variable name (or a reference) from surrounding text,
like ${1}2345 or ${12}345.  Use the same for freeswitch too.

While at it, fix a buffer overflow as well: the index[] variable
which is used to copy the "variable" name is 10 chars long, but
it is used in the code without bounds checking, so a reference
which is >9 chars long ($1234567890) will overflow the buffer,
crashing freeswitch.

And another overflow is in the way how size of the "substituted"
variable is handled.  First, in the outer loop, we compare the
wrong variable with the size of `substituted' buffer (amount of
bytes we took from the source instead of amount of bytes we
used in `substituted').  And second, when actual regex match
is being substitured, amount of room in `substituted' variable
is not checked at all.

Patch contributed by Michael Tokarev <mjt@tls.msk.ru>