Restructure optimize command and start command

[gkpty]

• Most parts of the start command should be part of the dev_server module which will contain all of the web_pack dependencies, etc.
• Most parts of the the optimize command should actually be a part of the dev_server module.
• The optimize command should be changed to build instead of optimize.
• the optimize module should be renamed to seo_fix
• the audit module should be renamed seo_audit