optionFindValue - find a hierarcicaly valued option instance

       This  routine  will  find  an entry in a nested value option or configurable.  It will search through the
       list and return a matching entry.

       odesc  an option with a nested arg type

       name   name of value to find

       val    the matching value

       The returned result is NULL and errno is set:

       EINVAL - the pOptValue does not point to a valid hierarchical option value.

       ENOENT - no entry matched the given name.  @end itemize

       optionFindValue - find a hierarcicaly valued option instance

       a compound value structure

       The info documentation for the -lopts library.
       ao_string_tokenize(3),  configFileLoad(3),  optionFileLoad(3),   optionFindNextValue(3),   optionFree(3),
       optionGetValue(3),   optionLoadLine(3),   optionMemberList(3),   optionNextValue(3),  optionOnlyUsage(3),
       optionPrintVersion(3),      optionPrintVersionAndReturn(3),      optionProcess(3),      optionRestore(3),
       optionSaveFile(3),    optionSaveState(3),    optionUnloadNested(3),    optionVersion(3),    strequate(3),
       streqvcmp(3), streqvmap(3), strneqvcmp(3), strtransform(3),

                                                   2018-08-26                                 optionFindValue(3)

       #include <your-opts.h>
       cc [...] -o outfile infile.c -lopts [...]

       const tOptionValue * optionFindValue(const tOptDesc * odesc, char const * name, char const * val);