[Fix] Add missing license info and author info for FMDB podspecs.
Add FMDB.podspec 1.5.1 and 2.0.
FMDB needs to link against sqlite3
removed FMDB example from Podspec
FMDB example file (fmdb.m) contains `main` function which will cause
compile error when including FMDB to a project as a dependency
updated FMDB spec to use tagged version (thanks to @ccgus!)
added FMDB podspec