Remove build-essential from mysql recipe

This recipe is not required and is conflicting with the mysql cookbook
resulting in 'apt-get update' not being run.
Fix crash in proxy recipe when ssl=false
add support for LDAP authentication
allow specify a arbitrary number of ldap parameters
The ldap provider config is complicated so it is hard to know in advance
all parameters, this change allows more flexibility in ldap configuration
add support for specifying sendemail config
set default sendemail.smtpServer to localhost when
node['gerrit']['sendemail'] is not specified
Merge pull request #2 from QuickbridgeLtd/sendemail

set default sendemail.smtpServer to localhost when
allow to specify gerrit container parameters
Merge pull request #3 from QuickbridgeLtd/container

Allow to specify gerrit container parameters
fix error in gerrit container setting
Merge pull request #4 from QuickbridgeLtd/container

fix error in gerrit container setting
Make replication configurable
Merge pull request #5 from QuickbridgeLtd/feature/replication

Make replication configurable
fix problem happened when git replication is disable
Merge pull request #6 from QuickbridgeLtd/huy

Fix cookbook error when replication is not enabled
Fix missing variable in default.rb
Merge pull request #7 from QuickbridgeLtd/paul

Fix missing variable in default.rb
Merge pull request #9 from QuickbridgeLtd/master

* Remove build-essential from mysql recipe
* Fix crash in proxy recipe when ssl=false
* add support for LDAP authentication
* add support for specifying sendemail config
* allow to specify gerrit container parameters
* Make replication configurable