In the past, it was often[1] forgotten for xlators to be linked against
the symbols they refer to. This often caused glusterd2 to fail while
loading xlator's shared object (.so) file.

This change adds "--no-undefined" as a linker flag which causes the
linker to treat unresolved symbol references as an error and hence fail
linking.

[1]:
https://review.gluster.org/#/c/19912/
https://review.gluster.org/#/c/19664/
https://review.gluster.org/#/c/19056/
https://review.gluster.org/#/c/17659/
https://bugzilla.redhat.com/show_bug.cgi?id=1532238

Bonus:
Added cloudsync and utime xlator's generated source files to .gitignore

Updates: bz#1193929
Change-Id: I9604a4a87b7313a5fa43bda5fdb37dfa7ef8facd
Signed-off-by: Prashanth Pai <ppai@redhat.com>

Before creating any file negative lookups(1 in Fuse, 4 in SMB etc.)
are sent to verify if the file already exists. By serving these
lookups from the cache when possible, increases the create
performance by multiple folds in SMB access and some percentage
in Fuse/NFS access.

Feature page: https://review.gluster.org/#/c/16436

Updates #82
Change-Id: Ib1c0e7ac7a386f943d84f6398c27f9a03665b2a4
BUG: 1442569
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: https://review.gluster.org/16952
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>