* Deprecate fisher --list in favor of a new command fisher list.
The behavior is roughly the same. See fisher help list for
usage. tl;dr: Use list to query the local system / cache and
search to query the index.
* Teach fisher_plugin_walk about fish_postexec,
fish_command_not_found and fish_preexec event emitters and
erase them during uninstall if they were defined in a snippet.
* Fisherman now recognizes the following aliases by default:
i for install, u for update, l for list, s for search and h
for help.
* Large documentation rewrite. Better, simpler, more concise
and more consistent.
* Fisherman now detects if users have modified their fish
prompt using fish_config and if so, uninstalls $fisher_prompt.
