Description of problem:
Failed to tail app logs with options like -o '-n 100'.

Version-Release number of selected component (if applicable):
rhc-0.85.11-1.el6_2.noarch

How reproducible:
Always

Steps to Reproduce:
1.Create an openshift app
# rhc app create -a app1 -t php-5.3
2.Tail logs using options like "-o '-n 100'"
# rhc app tail -a app1 -p redhat -o '-n 100'
or
# rhc app tail -a app1 -o '-n 100'
3.
  
Actual results:
If you specify the password:
<---------output------------->
# rhc app tail -a app1 -p redhat -o '-n 100'
/usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/bin/rhc-app:457:in `show_logs': uninitialized constant Base64 (NameError)
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/bin/rhc-app:575
	from /usr/bin/rhc-app:19:in `load'
	from /usr/bin/rhc-app:19
<---------------------------->
If you don't specify the password:
<---------output------------->
# rhc app tail -a app1 -o '-n 100'
Password: /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/lib/rhc-common.rb:289:in `gets': No such file or directory - 100 (Errno::ENOENT)
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/lib/rhc-common.rb:289:in `get_password'
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/bin/rhc-app:123:in `validate_args'
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/bin/rhc-app:435:in `show_logs'
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.85.11/bin/rhc-app:575
	from /usr/bin/rhc-app:19:in `load'
	from /usr/bin/rhc-app:19
<---------------------------->

Expected results:
Logs should be tailed successfully.

Additional info: