Use LITE_RUNTIME option.

This way we can link to the smaller libprotobuf-lite. We can't use
reflection, but thats not really needed in most cases.

src/fileformat.proto

@@ -15,6 +15,7 @@
 
 */
 
+option optimize_for = LITE_RUNTIME;
 option java_package = "crosby.binary";
 package OSMPBF;
 

src/osmformat.proto

@@ -15,6 +15,7 @@
 
 */
 
+option optimize_for = LITE_RUNTIME;
 option java_package = "crosby.binary";
 package OSMPBF;