Support compound multi-value option strings in presets

The JABAWS API allows a program to discover which options and parameters are enabled in a particular preset for a service. Jalview uses this to display the options/parameters for particular presets.

JWS-50 revealed a problem with the API for listing the options enabled for a service, which meant that programs using the API cannot list the options enabled if a preset includes a concatenation of arguments for 'multivalued options' which allow many values at once. The AACon service demonstrates the problem:

The patched AAConWS service supports a set of options like:

-m=SHENKIN
-m=SMERFS
-m=VALDAR

However, preset definitions most naturally specify combinations of command line arguments like:
-m=SHENKIN,SMERFS,VALDAR

rather than the more verbose:
-m=SHENKIN -m=SMERFS -m=VALDAR

Both combinations are valid for the AACon program, but the JABAWS client is not able to list the options for presets defined using the compact comma-separated form, resulting in JAL-1127