Merge changes from the v1.4 branch.
BUMP 1.5.0alpha1
Back to -dev.
PHP-990: Fixed overlooked fixme, using the connection bson size
PHP-987: Read maxWriteBatchSize from isMaster()
vim fold markers
Fix segfault when executing the same batch multiple times
Rollback the document from the buffer when overflowing it
missing closing folding tag
Add php_mongodb_batch type to track individual bulk batches
PHP-987: Split Batch Writes into multiple batches automatically

We split the batches when hitting maxWriteBatchSize, or maxBsonObjectSize
PHP-987: Add support for ordered and unordered batches

Write Options can now be passed in the ctor, and the write concern
preferences are "inherited" when the object is constructed, rather
then being fetched upon calling ->execute()
Fix zts
PHP-987: Fixed reusing the batch object for a new batch
Fix skipifs & update titles
Refactor code out of the actual methods, just keep zval stuffz there
Move Batch API functions into api/batch.{c,h}
Rename methods for API consistency
Ops. Include my headers
git grep -l php_mongodb_ | xargs perl -p -i -e 's/php_mongodb_/php_mongo_/g'