(also adding missing shebang lines)

- mbuild.sh: don't require bash
- Slackware/i2p/doinst.sh: add bash shebang

OpenBSD compilation fix: set JAVAC in bundle targets if javac not found and require.gettext is set to true

This solves the following problem which was found on OpenBSD:

bundle:
     [exec] Generating net.i2p.desktopgui.messages_ar ResourceBundle...
     [exec] ERROR - msgfmt failed on locale/messages_ar.po, not updating translations
     [exec] msgfmt: Java compiler not found, try installing gcj or set $JAVAC
     [exec] msgfmt: compilation of Java class failed, please try --verbose or set $JAVAC
     [exec] 9 translated messages.


In OpenBSD 5.4, neither java nor javac are in the PATH.

- check status of i2psvc with ldd
- only warn about libiconv in FreeBSD if the package isn't installed. In recent
  versions of FreeBSD, OpenJDK depends on libiconv so it should always be
  available.

   - Eepsite index.html better help on redirects
   - Remove exotrack (again)

	finishInboundEstablishment()

	so they can be used everywhere

   Rebuild router identity if key length doesn't match setting.
   This affects RI and LS encryption keys, and DH and YK.
   Faster = 64 bit with working jbigi, non-ARM, non-GNU (for now)
   Override default with crypto.elGamal.useLongKey=true/false
   LS key is built at client startup (Dest key unused)
   This will churn most of the RIs at the release.
 * SystemVersion: Add isARM()

 * NativeBigInteger: Don't use native for negative arguments, which aren't supported in jbigi.c

 * Jetty: Increase maxIdleTime