Added support for scope notation at nss_base_passwd and alternative
attribute sshPublickey.
Bugfix: Fixed issue with no arguments given and when config file cannot
be foud or read.
Now using fallback_logfile var when checking for existing configfile.
Added ability to use ldap.secret file and rootbinddn.

- Added ability to use ldap.secret file as alternative to bindpw
- Added ability to use rootbinddn as alternative to binddn
- Added some extra validations to mandatory config settings
Added ability to start a TLS connection
Added ability to support multiple nss_base_passwd entries.

- Fixed issue were keys and values from ldap.conf file were converted to
  lower case, now only the keys are converted to lower case.
- Fixed reading secret from ldap.secret file.
- Refactored code to read lines from a file.
Added ability to support multiple URI entries for failover purpose.

- Added support for multiple URI entries for connection failover in case
  an LDAP server doesn't respond.
- Added tls_cacertfile as cafile when connecting with TLS.
Merge pull request #4 from ivdmeer/master

Extra features