Generalize grub2 pattern

GRUB2 helper programs can be named either grub2-* or grub-*, depending
on distro and configuration.
Label grub2-install as bootloader_exec_t
Module version bump for bootloader fc fixes from Luis Ressel.
Merge upstream master
Dontaudit screen asking for the sys_tty_config capability

This avc shows up when using screen as root, however screen seems to
work fine without that permission.
Move screen dontaudit rule.
Module version bump for screen fix from Luis Ressel.
Merge with upstream contrib
Create .gitignore

This .gitignore file ignores every file which is removed by "make clean"
Merged with upstream
git: fix file pattern after whitespace fixes

Commit bb7d721c "Whitespace fixes in git.fc." removed the last letter of a
file pattern in git.fc. This patch adds the letter back.
Module version bump for git fc fix from Nicolas Iooss.
Merge with upstraem
Bump module versions for release.
Update Changelog for release.
Add several fcontext for debian specific paths for ntp

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=740656
Whitespace fix in ntp.fc.
Module version bump for ntp fc entries from Laurent Bigonville.
Bump module versions for release.
Fix parallel build of the policy

Before this commit, "make -j2" would execute twice at the same time the rules
written to build tmp/all_post.conf because these rules were applied every time
tmp/all_post.conf, tmp/all_attrs_types.conf and tmp/only_te_rules.conf needed
to be built. However, executing twice in parallel such line is buggy:

    $(GREP) '^fs_use_(xattr|task|trans)' $(tmpdir)/all_te_files.conf >> \
        tmpdir)/all_post.conf

This is why "make" reports following error for parallel builds:

    Compiling refpolicy-patched base module
    /usr/bin/checkmodule -M -U allow base.conf -o tmp/base.mod
    /usr/bin/checkmodule:  loading policy configuration from base.conf
    policy/modules/kernel/ubac.te":710:ERROR 'syntax error' at token
    'fs_use_trans' on line 26520:
    fs_use_trans devtmpfs system_u:object_r:device_t:s0;

    /usr/bin/checkmodule:  error(s) encountered while parsing configuration
    make: *** [tmp/base.mod] Error 1

This commit fixes this bug by splitting the rules in 3 different targets, in
both monolithic and modular builds.