[logback-dev] Reverted logback license back to LGPL

Hello all, I have reverted the logback license from GPL+classpath exception to the original LGPL. Given that GPL+classpath exception proved as controversial as the original LGPL, there is no point in changing for more of the same. Note that the previous license (GPL+classpath) was introduced in SVN on April the 8th, 2008 and was marked as tentative. Moreover, GPL+classpath was never used in a logback distribution. Just cleaning up... -- Ceki Gülcü