cmake: find packages (Boost & pthread)

See merge request zdvresearch_bsc/adafs!14

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

IOR support and I/O threading improvements

See merge request zdvresearch_bsc/adafs!12

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.

Cmake and project cleanup

See merge request zdvresearch_bsc/adafs!10

daemon related cmake directives have been pushed into a standalon cmake
file into the src/daemon folder.

- 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

FILE_OFFSET_BITS flag was required for Fuse builds and is a remnant
from previous fs versions. Currently it is not required

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

- lseek() added
- OpenFileMap rebuild with tmpfile syscall removed. Flag handling improved
- dup() and dup2() added
- read/write is now using Argobots ES for each thread
- Mercury version bump for local I/O to work with eager mode

The specific version is necessary for local I/O to work.

Added lseek64 syscall and used file flags properly