Several issues are resolved:
* Internally, floats were used for timestamp values but this could result
in wrapping so they've been changed to doubles.
* Historically, the default CEL eventtime format is `<seconds>.<microseconds>`
with `<microseconds>` always being 6 digits. This should have continued to be
the case but res_cdrel_custom wasn't checking the `dateformat` setting in
cel.conf and was defaulting to `%F %T`. res_cdrel_custom now gets the default
date format from cel.conf, which will be whatever the `dateformat` parameter
is set to or `<seconds>.<microseconds>` if not set.
* The timeval field formatter for both CDR and CEL wasn't handling custom
strftime format strings correctly. This is now fixed so you should be able
to specifiy custom strftime format strings for the CEL `eventtime` and CDR
`start`, `answer` and `end` fields. For example: `eventtime(%FT%T%z)`.
Resolves: #1844Resolves: #1845
80b953f76f