DB console doesn't run for all Windows-based ruby implementations

On some implementations of ruby on Windows, DB console will not run because it will not be able to find the database client executable.

This is because DB console fails to recognise it is running on Windows, and therefore does not know to add ".exe" to the file executable file name.

The following code shows what happens in the current released version (2.3.5), and what happens when I modify the edge version to fix the problem, when running against RubyInstaller:

C:\Documents and Settings\agrimm\Desktop\code>irb
irb(main):001:0> puts RUBY_PLATFORM, RUBY_VERSION
i386-mingw32
1.9.1
=> nil irb(main):002:0> exit

C:\Documents and Settings\agrimm\Desktop\code>cd rails_2_3_5

C:\Documents and Settings\agrimm\Desktop\code\rails_2_3_5>ruby script\dbconsole
Couldn't find database client: sqlite3. Check your $PATH and try again.

C:\Documents and Settings\agrimm\Desktop\code\rails_2_3_5>cd ..\with_console_db_fixed

C:\Documents and Settings\agrimm\Desktop\code\with_console_db_fixed>rails dbconsole
SQLite version 3.6.23.1
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .exit

The code involved was like this in version 2.1.0