Improved support for GNU/kFreeBSD

- add kFreeBSD to NBI and CPUID
- add kFreeBSD to jcpuid/jbigi build scripts
- refresh debian patches to compensate for kFreeBSD changes
- i2prouter: Detect kFreeBSD and normalize its name
- clean up osid (switching to "elif") and adding support for detecting kFreeBSD
- update postinstall.sh; I2P cannot be installed using gij so postinstall.sh
  will not be run. If/when openjdk finally comes to kFreeBSD, we'll be ready for it.

debian/patches/0002-jbigi-soname.patch

@@ -12,8 +12,8 @@ a soname to shut lintian up.
 
 --- a/core/c/jbigi/build_jbigi.sh
 +++ b/core/c/jbigi/build_jbigi.sh
-@@ -37,7 +37,7 @@
-             UNIXTYPE="solaris"
+@@ -39,7 +39,7 @@
+             UNIXTYPE="linux"
          fi
          COMPILEFLAGS="-fPIC -Wall"
 -        INCLUDES="-I. -I../../jbigi/include -I$JAVA_HOME/include -I$JAVA_HOME/include/${UNIXTYPE}"
@@ -21,7 +21,7 @@ a soname to shut lintian up.
          LINKFLAGS="-shared -Wl,-soname,libjbigi.so"
          LIBFILE="libjbigi.so";;
  *)
-@@ -56,7 +56,7 @@
+@@ -58,7 +58,7 @@
  
  echo "Compiling C code..."
  rm -f jbigi.o $LIBFILE