NoTgzBuilder - do not guess source, get it correctly from spec file
Add install instructions
Merge pull request #60 from practicalweb/master

Add install Instructions
do not fail if spec does not have any source

addressing:
Error running command: /usr/bin/spectool --list-files '/tmp/tito-build/rpmbuild-ruby193-d6e54d8c72c34196a4f51ac134c4172b44d9eccae0bLpW/SOURCES/ruby193-1/ruby193.spec' | awk '{print $2}' |xargs -l1 basename
Status code: 31488
Command output: basename: missing operand
Try 'basename --help' for more information.
Traceback (most recent call last):
  File "/usr/bin/tito", line 23, in <module>
    CLI().main(sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/tito/cli.py", line 94, in main
    return module.main(argv)
  File "/usr/lib/python2.7/site-packages/tito/cli.py", line 401, in main
    return builder.run(self.options)
  File "/usr/lib/python2.7/site-packages/tito/builder.py", line 194, in run
    self.srpm()
  File "/usr/lib/python2.7/site-packages/tito/builder.py", line 228, in srpm
    self.tgz()
  File "/usr/lib/python2.7/site-packages/tito/builder.py", line 479, in tgz
    result = run_command(cmd)
  File "/usr/lib/python2.7/site-packages/tito/common.py", line 217, in run_command
    raise Exception("Error running command")
Exception: Error running command
Fixed check for existing tag

We use suffix in relase number to indicate build in a branch. Builds from master have no suffix.
When we had package-1.2.3-4h built in branch and was trying to tag package-1.2.3-4 in master
the check failed as the new tag was substring of the other tag and grep matches that.
Merge pull request #59 from xsuchy/sources

NoTgzBuilder - do not guess source, get it correctly from spec file
Merge pull request #62 from mbacovsky/tag_checker_issue

Fixed check for existing tag
Allow user to define which package need to be installed before tagging.

This is for supporting tagging software collections (SC), if you have
installed meta package of SC then then name of package is different.
I.e. if you are tagging rubygem-foo package and you have ruby193-build
installed then the name of package is ruby193-rubygem-foo.
allow tagger to get values from package config and override values in global_config
merge common code from tagger and builder
Merge pull request #63 from xsuchy/pull-req-sc3

Support tagging packages from Software Collections