Make ucl_object_find_key[l] support finding an array index, as well as a
key

Make ucl_object_insert_key_common (and by
extension: ucl_object_replace_key, ucl_object_insert_key_merged, etc)
access an array index in place of a key if the object is an array
Remove some debugging
Remove more debugging
Implement ucl_object_mix_key, to combine 'merge' and 'replace' modes,
to overwrite keys that conflict, rather than creating arrays
Implement ucl_array_merge to merge two arrays
Implement ucl_object_merge()
Move (or copy) elements from 1 UCL_OBJECT to another
Fix build errors, extraneous }
Implement ucl_object_merge()
References (or copies) all elements from one object into another
Style
Improve documentation for most functions that return an object
Merge branch 'master' of github.com:vstakhov/libucl
Sync with upstream/master (vstakhov/libucl)
Merge branch 'master' of github.com:vstakhov/libucl into object_merge
style
Merge branch 'array_merge' of github.com:allanjude/libucl
Merge branch 'object_merge' of github.com:allanjude/libucl
Grammar fix
Merge pull request #50 from allanjude/patch-2

Grammar fix in documentation of ucl_array_append()
Merge pull request #49 from allanjude/inline_docs

Improve documentation for most functions that return an object
Merge pull request #47 from allanjude/array_merge

Make ucl_array_merge() take a reference instead of moving the elements