Log: allow hiding info messages

Fixes #131
Rename RecentChanges module to Filters

Also reduce line length
Log: scroll to bottom after re-showing info messages
Log: split _makeLogArea
Log: link to save the log

Addresses #146
Log: allow hidden messages

Addresses #146
Log: use a prettier link than a checkbox for showing/hiding info messages
Log: use a space to separate links
Diff: decode URI component, otherwise the query may fail
LOCAL: update paths for local configuration
scriptish-local-hack.sh

Unless `extensions.scriptish.cache.enabled` [1] is `true`, Scriptish loads scripts from disk each time they are required. Linking the scripts in Scriptish profile directory into git tree allows easier development, it is not necessary to reinstall Wiki Monkey after each change.

[1]: https://github.com/scriptish/scriptish/wiki/Manual%3A-Preferences#wiki-boolean-extensionsscriptishcacheenabled--new-in-scriptish
scriptish-local-hack: use programmatic approach
scriptish-local-hack: safe_ln() is useless, it is already ensured that target exists