[Rpm-ecosystem] Special meaning of "+" (?) separator

[Igor Gnatenko]

Hi,

during process of getting tilde approved in Fedora Packaging
Guidelines we realized that we need some special handling for
separator (most probably) "+".

Some examples (left is what expected, right is what current situation):
1.0+ > 1.0              | 1.0+ == 1.0
1.0+20160101git < 1.0.1 | 1.0+20160101git > 1.0.1

During long discussion at #rpm.org on freenode with Florian and Panu:

1. Florian didn't like to change behavior of "+" as it's already
allowed character and people might expect it to do something
different.
2. From alternative symbols we needed to choose from: "@", "#", "^"

After thinking more about problem I realized that we probably just
change behavior of "+".
Some questions are still in my mind:
* vercmp: 1~ ? 1+
* How "+" should be handled in (Build)Requires?
    * BuildRequires: foo == 1+ should match 1+, 1+git, 1+whatever ?
    * BuildRequires: foo >= 1 should match 1, 1.1, 1+git, 1.1+whatever ?
    * BuildRequires: foo < 1+ should match 1, 1~git, 0.whatever ?

Thoughts? Suggestions?
-- 
-Igor Gnatenko