* Support Upgrade From Older Versions
First I've added a MySQL Root Password Prompt, it will verify that the user is entering the correct password and will not continue until the MySQL Root Password is entered correctly.
Second, I'm just getting the tomcat version number from /etc/ folder name...This seems to work well enough (instead of making the user edit the script manually)...Maybe someone can come up with a better solution?
Third, I'm using the Version.js file to get the currently installed versions number. This allows for supporting multiple version number upgrades (E.G going from 0.8.2 to 0.9.14). The script will now loop through all of the SQL Upgrade files, and apply any that are newer than the OLDVERSION...
I.E. Going from 0.9.9 to 0.9.13 should automatically install `upgrade-pre-0.9.10.sql` & `upgrade-pre-0.9.11.sql` & `upgrade-pre-0.9.13.sql`
* Remove GUACAMOLE_HOME
According to the documentation this is now a default search path, so this isn't required anymore
* Version Control for Ubuntu and Debian
This might need more work but it should install the proper packages for both Ubuntu and Debian and account for Tomcat 8.0.x and 8.5.x differences...
http://tomcat.apache.org/whichversion.html
7.x does not say end of life... but 8.0.x does. The distro maintainers have different versions of Tomcat8 so we can check for 8.5.x or newer options and install, otherwise go the safer route and install Tomcat7
* Remove rm and ln of tomcat/.guacamole
According to the documentation this is not required (it may not have been required to begin with?)
* No Longer Incubating!
* fixed typo
* fix typos; use mkdir -p
fix a couple of minor typos and some unnecessary caps; switch to mkdir -p (create parent directories) in Make Directories section to save one line and prevent errors if directories already exist
* switch from apt-get to apt; lose -qq for install
* fix typo
* Tomcat Variable
I don't know a good way to know which tomcat version is already running, and of course someone could theoretically run more than one...so the upgrade script is just a variable but the install script will check apt-cache and try to install tomcat8, then tomcat7, then tomcat6...
* Optional commented line
Added a commented out line in case someone wants to force an older/specific tomcat install
I split apt-get into multiple lines so it wasn't just one long line across the screen.
I also split the SQL database creation by converting it to a multi-line variable
Added more comments
If apt-get fails, likely due to missing dependencies or differing names outside of Ubuntu 16.04.01 LTS official sources, we should just exit and inform the user, no need to keep going...
