Since POSIX.1-2001 the S_IFMT (0170000) bitmask of the file mode must
contain the file type.

At the moment we correctly support
 - [S_IFREG] regular file
 - [S_IFDIR] directory

Previously, clients would look for the daemon by name which was not robust.
If the daemon was started with valgrind for example, clients would not find
the daemon.

Similar to other applications a daemon now creates a pid file with
information about its pid and its started mountdir.

Proper errorhandling on server and client side was added.

Multiple daemons per node are explicitly not allowed for now!

target was the index of the cycle and target[target] was the actual
identifier of the target. In some part of the code target was considered
as the identifier directly.

Now the index of the cycle is i and target is the actual identifier of
the target.

The calculus (on clients) about the last chunk involved into a
write/read operation was bugged.

A new blocks_calc_util library has been introduced in order to make
easier to perform this kind of calculus.

Instead use margo_iforward. Also only two bulk_handles are now used:
1 for margo_ipc and one for margo_rpc RPC requests.

The LRU map caused multiple issues with memory mappings and caused
severe errors and hanging situations. It has been replaced with a
std::map.

An Argobots mutex was added for rpc address lookups as many threads
might insert and lookup this map in parallel. This caused bulk_transfer
seqfauls as well as other file system crashes.

Cleanup of file system logging.

Before data was pulled first then written or read first and then pushed back

Only use 1 segment now but with multiple transfers

Use cmake in order to properly check and use both the Boost library and
the pthread one.

We need to be explicit about I/O as it cannot be simply repeated. A response
from the daemon will come eventually, either success or failure.

Previously, an ES was created for each destination in each read or write.
Creating and freeing these ES is costly. Also, these ESs had separate pools,
which is bad practice. Multiple ESs work on a single pool. The ABT_sched
decides which ULT or Tasklet is run by which ES at any time.

This change does also reduce CPU load as library IO RPC calls used CPU time
while waiting for the response.

- Previously the directory hierarchy was not clear regarding to which
  file belong to which part of the project (client or daemon).
  Further, we will have other clients in the future (such as Fuse).
- CMake files now differentiate between include dirs for all targets
  and target specific ones.
- Removed duplicate -pg flag.
- Not listing header files when adding executables or libraries
  is considered bad practice. Note that include_directories() is adding
  include paths to the code while adding all files used for executables
  and libraries provide the context which files belong to each binary.
  When only include_directories() is set, CMake assumes that all files
  belong to a binary (which is not necessarily true). As a result,
  some IDEs may break as the do not support this assumption.

  In general we should almost always favor explicitness over implicitness.

The preload specific cmake files inherits the global flag declarations,
thus it is not necessary to specify again all the flags.
Moreover the only addition made by this declaration is the `-fPIC` flag.
According to the official CMake docs [1], is set automatically for
library target as SHARED. Thus we don't need to set it explicitely.

[1]: https://cmake.org/cmake/help/v3.6/prop_tgt/POSITION_INDEPENDENT_CODE.html

Subprojects specific CMakeLists.txt inherits directives from the main cmake file.
Thus it is not necessary to replicate global level directives

since we use the `include_directories(include)` it is not necessary to
explitely specify all the headers file in the source list.

ADA-FS's statfs will fill the struct mostly with rough estimations.
It is not supposed to return accurate data but "some" data for applications to work