Update transistor reference packages

[p12tic]

• Added TO-220 package family to ref-packages-transistor.lbr: TO220-AB, TO220-AB-H, TO220-AC, TO220-AC-H, TO220-F, TO220-F-H.
• Added SC74-5 and SC74-6 packages to ref-packages-transistor.lbr.
• Updated the land patterns of all packages within ref-packages-transistor.lbr to ones recommended by NXP for reflow soldering. In all cases the updated land patterns were already used by at least one existing library prior to cleanup.
• Removed a number of packages that were different from the reference packages only by pin naming.
• Removed wave soldering versions of transistor packages. Also removed versions with long solder lands.
• Synchronized packages with the new contents of ref-packages-transistor.lbr. Manual verification has been done in all cases. There were no cases where the size of solder lands became larger than the previous size before the cleanup.

The names of the newly added packages:
TO220-AB
TO220-AB-H
TO220-AC
TO220-AC-H
TO220-F
TO220-F-H
SC74-5
SC74-6