Ophal installer

Ophal is not based on traditional web technology, but it should not be a limitation. RoR and Django know it well!

Following the specification of Ophal installer a.k.a install.cgi:

    -- Step #0: index.cgi looks for settings.lua, if not found then redirect
                to install.cgi
    -- Step #1: Look for settings.lua
      -- If found then goto Step #5
    -- Step #2: Print welcome page
      -- Hint #1: For enhanced security, do *not* run this install wizard in production.
      -- Hint #2: This install wizard needs Javascript enabled to run.
      -- Hint #3: Please create a database.
    -- Step #3: Check requirements
      --  Look for settings.lua If not found then
        -- Check 'files' directory permissions
          -- If not writeable then say: Can't write to 'files directory', please
             change permissions. [Link to documentation website](http://ophal.org/manual/--version--/install#files-directory)
        -- Check 'libraries', both optional and required
          -- If some or none found then say: List of missing libraries, please
             install. [Link to documentation website](ophal.org/manual/--version--/install#libraries)
            -- pcall(require, 'library')
        -- Say: All requirements are OK
    -- Step #4: Ask for database, root user and site information
      -- Ask for database engine: SQLite (only, for now)
        -- SQLite: Ask for path to database file
      -- Ask for site name and other details
      -- Ask for root user name and initial pass
      -- Generate settings.lua, user should upload manually
    -- Step #5: Create tables and root user
      -- Try to read database connection.
      -- Try to connect to database
        -- If failed then say: can't connect to database, goto Step #4
      -- If system table says system module status equals to 1, then goto #6
      -- Create tables that does not exists (prevents overriding data)
      -- Mark system module status to 0
      -- Create root user if it does not exists
      -- Mark system module status to 1
    -- Step #6: Congratulations!
      -- Say: Site successfully install, go to frontpage(link to it)

May God bless Ophal!

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- Wall Time: 21.29 ms
- MemUse: 450.56 Kb