Add API to check if we support a specific Wire Version
WS
PHP-923: Extract [min|max]WireVersion from mongo[d|s]

If the WireVersion is not found, default to 0 for both min and max.
Update MongoLog tests for [min|max]WireVersion

These tests run on all versions of mongod so the matching has to
be very generic, effectively only testing if we write a entry
PHP-923: Add the Wire Version to MongoClient->getConnections()
PHP-923: Bail out on unsupported Wire Versions

When we hit a server running unsupported wire version we don't abort
right away. Instead, we continue our ReplicaSet discovery as usual
and abort before returning a connection.
This is done incase there are multiple errors that we need to
aggregate for the user, so he doesn't have to fix one server,
retry, fix another server and so on.
Fix segfault in MSHUTDOWN when rejecting servers due to Wire Version
Fix the error message on failure
Move default values to where we define the structure
Improve comments on the various wire version numbers
Rename variable to make it more clear what it means
Rename a variable and improve comments change if()s to switch/case
Match all digits
s/php_mongodb_/php_mongo_/g
Fix Windows and pecl builds after the new api/wire_version.* files
Consistencify WireVersion in comments
Change the error message a little
s/WireVersion/wire version/g as per code review
Merge pull request #549 from bjori/PHP-923-maxWireVersion

PHP-923: Drivers should only talk to servers with overlapping wire versions

* bjori/PHP-923-maxWireVersion:
  s/WireVersion/wire version/g as per code review
  Change the error message a little
  Consistencify WireVersion in comments
  Fix Windows and pecl builds after the new api/wire_version.* files
  s/php_mongodb_/php_mongo_/g
  Match all digits
  Rename a variable and improve comments change if()s to switch/case
  Rename variable to make it more clear what it means
  Improve comments on the various wire version numbers
  Move default values to where we define the structure
  Fix the error message on failure
  Fix segfault in MSHUTDOWN when rejecting servers due to Wire Version
  PHP-923: Bail out on unsupported Wire Versions
  PHP-923: Add the Wire Version to MongoClient->getConnections()
  Update MongoLog tests for [min|max]WireVersion
  PHP-923: Extract [min|max]WireVersion from mongo[d|s]
  WS
  Add API to check if we support a specific Wire Version
Updated README.