Import utlist 1.9.7
Replace elist.h with uthash.h for thread queue
Replace elist.h with uthash.h for scan_devices string list
Replace elist.h with uthash.h for pool curls
Replace elist.h with uthash.h for work lists (share submission and bitforce bqueue)
Remove elist.h and any final references to it
Remove embedded uthash (and add dependency on system uthash)
windows-build.txt: Update for system uthash
Remove embedded uthash.h and utlist.h from Makefile
Bugfix: Free work only after deleting it from list
Merge branch 'utlist' into bfgminer