java: Avoid warnings in the tests and examples.

Avoid warnings about missing serial version, and fix a warning about
raw types.
fish/uri: Initialize some variables to avoid a warning.

The warning only appears when we set CFLAGS to be the same as used by
RPM, which you can do by setting:

  CFLAGS="$(rpm --eval '%{__global_cflags}')"

before running ./configure.

FWIW the current value of that RPM expression (in Fedora 20) is:

  -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches

It is not clear which option precisely enables the warning.
gobject: Use spaces between function name and call parameters.

This is just a whitespace change.

This was done by running the following command and then fixing a
couple of places where it got it wrong:

perl -pi.bak -e 'unless (m/#define/) { s/([a-zA-Z0-9])\(/$1 (/g }' \
  generator/gobject.ml
gobject: Don't direct error messages to /dev/null.

We might want to see them.
gobject: Clean up some warnings about unused variables.
gobject: Remove some more warnings from session.c code.
mllib/uri-c.c: Remove unused variable.
builder: pxzcat: Fix char * signedness warning.