Delete lines 54-60 of ideviceinstaller.c.

The reason for this is that these lines are only useful for very old versions
of libzip, but those versions are now disallowed by the configure script.

This fixes issues #43, #50, #66, and (probably) #55.
diff --git a/src/ideviceinstaller.c b/src/ideviceinstaller.c
index 28b98ec..12f2caf 100644
--- a/src/ideviceinstaller.c
+++ b/src/ideviceinstaller.c
@@ -51,13 +51,6 @@
 
 #include <zip.h>
 
-#ifndef ZIP_CODEC_ENCODE
-// this is required for old libzip...
-#define zip_get_num_entries(x, y) zip_get_num_files(x)
-#define zip_int64_t ssize_t
-#define zip_uint64_t off_t
-#endif
-
 #define ITUNES_METADATA_PLIST_FILENAME "iTunesMetadata.plist"
 
 const char PKG_PATH[] = "PublicStaging";