Implement 1.0.0 Database Migration

[tierra]

Since this is a conversion from the 3.0.x Topic Solved MOD, the first migration should match the original database schema used:

ALTER TABLE phpbb_forums ADD forum_allow_solve tinyint(1) UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE phpbb_forums ADD forum_allow_unsolve tinyint(1) UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE phpbb_forums ADD forum_lock_solved tinyint(1) UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE phpbb_forums ADD forum_solve_text varchar(25) NULL;
ALTER TABLE phpbb_forums ADD forum_solve_color varchar(7) NOT NULL DEFAULT '';
ALTER TABLE phpbb_topics ADD topic_solved mediumint(8) UNSIGNED NOT NULL DEFAULT 0;

[tierra]

Partly implemented in #5, and polished off in d5281f52