v0.4

• webp2pam: always output actual PAM instead of sometimes PPM (now does TUPLETYPE RGB instead, already did RGB_ALPHA when applicable).
• pam2webp: replace all known Netpbm file extensions.
• Case-insensitive filename matching like v0.1 (oops!)
• Just use plain strings for the output fopen() call.
• Actually include version number in build.
• Code formatting tweaks.

64-bit Windows EXEs attached. See the README for usage.