Add comment of using JVM version 1.5_06-b05 in "Installing Java" section of Documentation.

Improvement

At the time of choosing a JDK it would've been nice to know about: http://jira.atlassian.com/browse/JRA-9198.
The warning was only found in the atlassian-jira.log after installation was already completed. We had JVM 1.5 already installed and decided to use it for Jira as well.
It would be nice to add the same warning in the "Installing Java" section of the documentation.

Suggested Location to place comment

Installing Java

Some JDK version notes:

To build JIRA from source, you will need JDK 1.4 or above
Older JIRA releases (JIRA 3.1.1 and earlier) do not work 100% with JDK 1.5 due to a JDK bug that affects filter subscriptions. The problem has been worked around in JIRA 3.2 and above.
For FreeBSD, you'll need JDK 1.4.2-p5 or above.