gluster-block release 0.4 is tagged.

This is the new stable version of gluster-block

Highlights:
----------
* add replacing block volume support (540e816)
* add block volume resizing support (cfa7677)
* add configuration generation support (4a0ac49)
* add load-balancing support across available target nodes (f6bb475)
* add logrotate support (73dd5ba)
* add libtirpc support (3ac1399)
* add auditlog support (8416247)
* add dynamic reloading of config (/etc/sysconfig/gluster-blockd) support (4d56cd0)
* add cli rpc timeout option support (2629966)
* add ability to create block volume with configurable ring-buffer size (34c4a6d)
* add capabilities(versioning) support to work with heterogeneous cluster (46f460f)
* add ablility to create block volume with existing backend file (450f7e8)
* add option for leaving the backend file without unlinking while deleting the block (7008073)
* save-config only alter given block configuration (17832a4)
* automatically align the target device size to sector size (e971593)
* fix various cli operations exitcode (dc0c037)
* reserve 10M space for meta-data store, this avoids op failures when block hosting volume is 100% full (812ca9a)
* add the gfapi version check, and use the api based on available version (dbb0b26)
* use slow zeroing if glfs_zerofill is not supported (7b11fb1)
* defend on minimum recommended kernel version (c521390)
* defend on dependencies version at runtime (8599bd6)
* on stop service, clear the target config only when tcmu-runner is running (6bc89f4)
* add travis-integration for build verification using docker (bb046e5)
* support volfile server (discovery service) setting through Env (471401c)
* create block volume with 'prealloc full' by default (e9faa8e)
* convert cli and remote threads to individual processes to fix contention in tirpc (f70857a)
* increase max backup files (/etc/target/backup/) count (ae79a80)
* fix high severity issues from coverity (d913aa7)
* fix leaks reported by asan (c3307ff)
* add a simple demo to README doc (08be8c9)
* add more test cases (b2cac85)

Other Notable Fixes:
-------------------
* add a script for upgrade time activities (f6b40cc)
* script to wait for bricks to come online (2d89eaf)
* inotify watch the directory not just file (ac702ac)
* correct some rpc socket setup bits (b246756)
* fix create failure with ring-buffer option (b512de2)
* fix block delete failure (a4de1ee)
* fix heap-buffer-overflow reported by asan (872016e)
* fix dereference of undefined pointer value (6f04510)
* add CRIT loglevel in logger (149255f)
* add simple gfapi access test (8d34b29)
* silent building as default with automake (07dd59a)
* read configfile line-by-line instead of allocating a fixed 32K buffer (a661484)
* fix memleak for GB_LOG_LEVEL (4a47361)
* dump all failure msgs to stderr (fd62ac4)
* fix memleak for errMsg (9f705e7)
* avoid socket double free (766f97e)
* introduce remote exit value GB_BLOCK_NOT_FOUND (0a65c01)
* defend on block not loaded and CLEANUPFAIL status with delete (43d0a74)
* report block is not loaded status with modify (0b0b7db)
* fix auth command args parsing with modify (5a180e9)
* cleanup json object releasing (38cac9a)
* replace strcat and strcpy with their secure versions (d7ebb69)
* make create size unit prefixes case insensitive (f03d641)
* update docs to the latest (1eb1507)
* and many more ...

Read more at [1] and [2]

[1] https://github.com/gluster/gluster-block/blob/master/README.md
[2] https://github.com/gluster/gluster-block/blob/master/INSTALL

Cheers!
