Documentation: Added Internal Server Error, MySQL server has gone awa…

…y, and Premature end of script headers to Troubleshooting section

docs/source/troubleshoot/common/index.rst

@@ -9,6 +9,9 @@ ThinkUp is a work in progress. Certain known problems can occur on different ser
    emaildisabled
    admindeactivated
    cacert
+   mysqlgoneaway
+   prematureend
+   internalservererror
    500
    outofmemory
    crawlfail

docs/source/troubleshoot/common/internalservererror.rst

@@ -0,0 +1,11 @@
+Internal Server Error, or blank page when loading ThinkUp
+=========================================================
+
+If loading ThinkUp shows a blank page, or you see an HTTP 500, you're likely experiencing an "Internal Server Error." 
+
+To troubleshoot this problem, check your server's Apache error logs, which will contain details of exactly what's going
+wrong. If you don't know where the error log is located on your web server, contact your web hosting provider to find
+out.
+
+Once you can see your web server error log, reload the ThinkUp page causing the error to see its details. :doc:`Send the
+error line in your log to the ThinkUp community to troubleshoot </contact>`. 

docs/source/troubleshoot/common/mysqlgoneaway.rst

@@ -0,0 +1,13 @@
+PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away
+=============================================================================
+
+ThinkUp is a data-intensive application that generates large tables and keeps the database connection open for
+extended periods of time during its crawl and queries. This means that accessing busy accounts on 
+low-powered shared web hosting packages in ThinkUp can results in database timeouts.
+
+To fix the "MySQL server has gone away" error, contact your web host about increasing your server's timeout
+configuration to the maximum value. Here's more information:
+
+http://dev.mysql.com/doc/refman/5.0/en/gone-away.html
+
+If that's not possible, export your ThinkUp data and install ThinkUp in a server environment with more liberal timeouts.

docs/source/troubleshoot/common/prematureend.rst

@@ -0,0 +1,14 @@
+Premature end of script headers
+===============================
+
+If you're seeing an error like "Premature end of script headers" in ThinkUp's Apache error logs, it means your web
+server is timing out before ThinkUp's action (usually the crawler output page) can complete.
+
+To fix this problem, contact your web hosting provider and ask them for two things:
+
+1.  To increase the amount of memory available for ThinkUp's use so that the application can run faster. For example,
+    Dreamhost's cheapest shared hosting package may time out when gathering data for busy accounts, but Dreamhost's
+    300MB VPS server (which costs around $15/month) will not.
+
+2.  To increase the PHP script timeout for PHP pages served for your account.
+