Merge pull request #292 from cduclos/master

ListMutableIterator && Buffer
Do not link Community to libldap
Remove duplicate selection of libraries for MinGW build
Move comparray from libpromises to cf-agent

(Related: #1973)
Fix edit_xml update of existing attribute, with acceptance test

Redmine 2034: https://cfengine.com/dev/issues/2034

The xmlNewProp() libxml2 call, used in SetAttributeInNode(), does not
alter the value of an existing attribute, resulting in an inability
to keep promises about the value of any existing attribute.

The xmlSetProp call will create an attribute that does not exist, so
replacing xmlNewProp with xmlSetProp resolves the issue.
Remove duplicate LogHashChange function: leftover after split
Include alloc.h to bring xmalloc to atexit.c
Use platform.h to include conf.h in alloc.h
Fix wrong #ifdef for GetUidConstraint
GetOwnerName has a separate implementation for mingw
Link to Nova-specific libcfexecd
Fix wrong macro name
Merge pull request #294 from mvpel/fix_xml_setattr

Fix edit_xml update of existing attribute, with acceptance test
Buffer memory strategy

Rewrote the whole memory allocation strategy for buffer.
Now data is preserved even in case of failures.
Printf now returns 0 to signal that a retry is needed.
Memory is allocated as it is needed, not by increments.
RefCount memory allocation

Forgot to check one memory allocation when attaching ref_counts.