Avoid the need for each driver to parse query parameters itself
by storing them directly in the virURIPtr struct. The parsing
code is a copy of that from src/util/qparams.c  The latter will
be removed in a later patch

* src/util/viruri.h: Add query params to virURIPtr
* src/util/viruri.c: Parse query parameters when creating virURIPtr
* tests/viruritest.c: Expand test to cover params
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of just typedef'ing the xmlURIPtr struct for virURIPtr,
use a custom libvirt struct. This allows us to fix various
problems with libxml2. This initially just fixes the query vs
query_raw handling problems.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Move error reporting out of the callers, into virURIParse
and virURIFormat, to get consistency.

* include/libvirt/virterror.h, src/util/virterror.c: Add VIR_FROM_URI
* src/util/viruri.c, src/util/viruri.h: Add error reporting
* src/esx/esx_driver.c, src/libvirt.c, src/libxl/libxl_driver.c,
  src/lxc/lxc_driver.c, src/openvz/openvz_driver.c,
  src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
  src/remote/remote_driver.c, src/uml/uml_driver.c,
  src/vbox/vbox_tmpl.c, src/vmx/vmx.c, src/xen/xen_driver.c,
  src/xen/xend_internal.c, tests/viruritest.c: Remove error
  reporting
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since we defined a custom virURIPtr type, we should use a
virURIFree method instead of assuming it will always be
a typedef for xmlURIPtr

* src/util/viruri.c, src/util/viruri.h, src/libvirt_private.syms:
  Add a virURIFree method
* src/datatypes.c, src/esx/esx_driver.c, src/libvirt.c,
  src/qemu/qemu_migration.c, src/vmx/vmx.c, src/xen/xend_internal.c,
  tests/viruritest.c: s/xmlFreeURI/virURIFree/
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Function xmlParseURI does not remove square brackets around IPv6
address when parsing. One of the solutions is making wrappers around
functions working with xmlURI*. This assures that uri->server will be
always properly assigned and it doesn't have to be changed when used
on some new place in the code.
For this purpose, functions virParseURI and virSaveURI were
added. These function are wrappers around xmlParseURI and xmlSaveUri
respectively.
Also there is one new syntax check function to prohibit these functions
anywhere else.

File changes:
 - src/util/viruri.h        -- declaration
 - src/util/viruri.c        -- definition
 - src/libvirt_private.syms -- symbol export
 - src/Makefile.am          -- added source and header files
 - cfg.mk                   -- added sc_prohibit_xmlURI
 - all others               -- ID name and include fixes