Merge pull request #2 from alexeyvo/development

Development
B-0 removed Visual Studio 2010 typecast warnings
B-0 fixed a couple of more warnings found compiling in 32 bits mode
Merge pull request #3 from jsbattig/fix_warnings

B-0 removed Visual Studio 2010 typecast warnings
B-0 fixed VS type warning
Add mongoc-stream-cnv-gridfs wrapper to hook on read\write without modify any src, add example
Implement compress/decompress functionality
Merge pull request #4 from alexeyvo/compress_encrypt

Implement compressing\decompressing using zlib while reading\writing cnv gridfs stream
Add ability to run callbacks before write chunk in mongo collection and after read from collection
Reimplement compress feature to compress each chunk for allow seek
Merge pull request #5 from alexeyvo/compress_encrypt

Reimplement compress feature to compress each chunk for allow seek
Update readme
Merge pull request #6 from alexeyvo/compress_encrypt

Update readme
B-0 removed reference to vld.h file
B-0 added proper casts to remove warnings due to datatype conversions
B-0 added cast to prevent warning when compiling in 64 bits
B-0 removed warning compiling in 64 bits with casts from 64 bits integers to 32 bits
Merge pull request #7 from jsbattig/fix_compilation

Fix compilation and warnings
Implement encryption of file
Merge pull request #8 from alexeyvo/compress_encrypt

Implement encryption of file
Add ability to autogenerate aes key from password