Disabled packages should show up in the 'ignored' section of the sidebar. Fixes #256.
Verified that the parser can handle import cycles.
Import cycles are detected before running `go test -cover`, which causes an infinite loop (known bug in go cover tool). Fixes #228
Add a command line param for test execution timeout.

Add a -timeout command line param with a 5 second default.  The command line value is only used if a *.goconvey
file does not add a more specific value with "-timeout=[value]".  Use "-1s" for an infinite timeout (on the command line or in a *.goconvey file).