Add support for CMPI trace logs

Tracing allows more fine-grained level of debug messages, additional to already
implemented log_debug, log_info and log_warning.

The trace messages are intended for developer, while the standard log messages
are intended for user / system admin.

Trace messages are sent to CMPI function CMTraceMessage. Not all CIMOMs support
it, the trace messages fall back to log_debug in this case.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Klaus Kämpf <kkaempf@suse.de>
Fixed passing NULL array from get_instance

I have a python provider and I want to return an instance with NULL value of
string[] (or any other array) property.

Therefore I have in my get_instance method:
model['MyProperty'] = pywbem.CIMProperty(
	name='MyProperty',
	value=None,
	type='string',
	array_size=0,
	is_array=True)

Under Pegasus CIMOM I get traceback, because Pegasus pedantically checks
property types;
  File "/usr/lib/python2.7/site-packages/cmpi_pywbem_bindings.py", line 761, in pywbem2cmpi_inst
      cinst.set_property(str(prop.name), data, ctype)
  File "/usr/lib/python2.7/site-packages/cmpi.py", line 809, in set_property
      return _cmpi.CMPIInstance_set_property(self, *args)
  CIMError: (1, '61')

This patch adds two checks for NULL value of array and makes sure that the
CIMOM really gets NULL value of the property.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Klaus Kämpf <kkaempf@suse.de>
Fix comment for CMPIInstance assignment [] operator
More comments in array processing of target_to_value
Fix comment
Fix CMPI_dateTime <-> Ruby conversions

Also move the conversion code from C to Ruby
Improve warnings, disallow char16 0 values
Clean up handling of NULL(-like) values in data_value()
cmpi.rb - reduce debug printing
Add improved Ruby testsuite

This testsuite runs a private sfcb based on a generated sfcb.cfg file,
loads the just-built Ruby cmpi provider .so file and tests providers
from test/rake/samples/provider, effectively testing cmpi-bindings for
Ruby.
Don't disable GC during upcalls, needs fix in Ruby 1.9
Support fallback if Broker#trace or Broker#log are not supported
Refactor Ruby providers dir setting for test sfcb
More debug environment value for sfcb/sfcc
Ignore tmp dir from rake test
Disable keepalive, stalls in sfcbd
Remove create_provider test, not implemented
Mark test/ruby as obsolete
Remove unused test
Bump version to 0.9.0