Form: User -> Custom Builds

Enhancement: Modify how the list of build is reported on the Custom Builds form. Currently it is just a text list on the page. Change is to have it be the same as on the Edit Attributes form (searchable) and with the same attribute name/description.

Or present the user with both options:

1. a full list that is easy to copy/paste/download as a text file and
2. "builds" pull-down list modeled after the Edit Attributes form

Bonus features for 2 above (functions could also be added to the Edit Attributes form, are useful).

A): include "copy" icon to copy the "full genome name" or the "dbkey" (both options) into the clipboard.

B): note which builds are only already named (effectively this just means that the dbkey name is taken) versus those that also are indexed with a .fasta/.2bit (even though .len is the trackster minimum, knowing which have fasta sequence is helpful).

C): add in some other metadata such as a list of associated indexes on this server (picard, sam, bowtie/tophat, etc).