[SSSD] [sssd PR#611][opened] Do not build the local provider by default

[fidencio]

   URL: https://github.com/SSSD/sssd/pull/611
Author: fidencio
 Title: #611: Do not build the local provider by default
Action: opened

PR body:
"""
Folks,

This series is the first attempt to avoid building the local provider by default. With we
only build it conditionally and the default is set to not build it. The problems:
- integration tests depend on the local provider: For this, I've changed our configure
line, specifying to enable the local provider;
- some unit tests depend on local provider: I've changed some tests (please, take a
careful look at those in order to be sure I'm not invalidating the tests) and worked
them around so they're still valid with both scenarios (building or not building the
local provider);

My **personal** preference would be to start using the **files** provider in our tests
instead of using the "local" one. However, I've faced some issues related to
the amount of users being find in some sysdb tests (ping me, we can discuss this either
here or in the #sssd channel) (maybe because it also finds the local users/groups created
on my machine?).

Again, this is a first attempt, let's discuss improvements needed :-)
"""

To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/611/head:pr611
git checkout pr611