Update Filter utility functions

- Write simple tests for multi_test
- Add get_attr_caseless function for improving Filter.Match
Make *Filter.matches case insensitive for attrs
Allow ext request message to have a buffer value in order to accomodate rfc3062 exop
Modified client to allow buffer as a value for exop
Merge pull request #159 from gfhuertac/master

Allow ext request message to have a buffer value
Fix error event handling for pooled clients

Do not emit error events if no listeners are present
lint/test cleanup
travis update
Merge from pfmooney/client-pool-events

Fix mcavage/node-ldapjs#162
Merge pfmooney/filter-case-attrs

Fix mcavage/node-ldapjs#155
Update buffertools dependency

Buffertools 2.0.1 is required to build on VC2013.
With the change to v2.x, the buffertools.extend() method must be called
to mimic the prototype extention behavior of the 1.x versions.

Fix mcavage/node-ldapjs#163
Remove buffertools dependency
Circumvent lack of 'close' event for tls sockets

It appears that in node.js (at least recent versions), the 'close' event
is not emitted by TLS sockets.  The CleartextStream class specifies that
the 'close' event is optional, so such operation is allowed.  In order
to compensate, the event can be trapped at the raw net.socket instead.

Fix mcavage/node-ldapjs#161
Merge pull request #5 from mcavage/master

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