Fix compilation on Mac OS which lacks _strupr, _strlwr, and _unlink
Merge pull request #1 from noa--/gridfs_macos

Fix compilation on Mac OS which lacks _strupr, _strlwr, and _unlink
Refactored code to allow it to compile on MacOS
Clear compiler warning on gcc

`*s++ =` yielded this:
warning: operation on ‘s’ may be undefined
Avoid one of the compiler warnings in bcon_test.c
Rename create and dispose to alloc and dealloc

As discussed in recent pull requests, this helps to clarify that these functions merely allocate and deallocate memory, and helps clarify the difference between destroy and dealloc.

I left alone `gridfile_create`, which both allocates and initializes.

Note also that there is no `mongo_dealloc` – that's handled by `mongo_destroy`.
Merge remote-tracking branch 'refs/remotes/Mongo/master' into mongo-master-pull-request-gridfs
Merge branch 'refs/heads/mongo-master-pull-request-gridfs' into development

Conflicts:
	src/gridfs.c
	src/gridfs.h
	src/mongo.c
	test/gridfs_test.c
Merge pull request #103 from noa--/strupr_warning

Clear compiler warning on gcc
Removed some warnings on mongo.c and warning due to repeated _CRT_SECURE_NO_WARNINGS when this is defined on Visual Studio compiler as a default define
Merge remote-tracking branch 'refs/remotes/Mongo/master' into mongo-master-pull-request-gridfs
Merge pull request #104 from noa--/bcon_test_warning

Avoid one of the compiler warnings in bcon_test.c
Merge pull request #105 from noa--/create_to_alloc

Rename create and dispose to alloc and dealloc
Merge pull request #106 from jsbattig/mongo-master-pull-request-gridfs

Mongo master pull request gridfs
Tests: Fix a likely off-by-one error which would cause reading off the end of `letters`, and make this a little more efficient
GridFS chunk_new: Initialize with the amount of space needed

This avoids automatically allocating about 1.5 x as much space as needed
GridFS: Replace conditional operator with easier to read MIN and MAX and remove an extra semicolon
GridFS: Rename pre- and post-processing funcs

 -  Rename `preProcessingFunc` to `readFilter` and `postProcessingFunc` to `writeFilter`
 -  Consolidate duplicate typedefs
 -  Make `srcData` parameter const
 -  Change binary data buffers from void* to char* for consistency with rest of driver
GridFS: Change return type of gridfile_get_oid for convenience
Add const qualifiers