[QRS detection] Profiling and Makefiles added

* Change:
  - Profiling macros and function added.
  - Makefiles added.

* Note:
  - Source is compiled as shared library and test program
    is linked to created shared library.
  - Shared library should be added to LD_LIBRARY_PATH or
    to one of common directories for libs in Linux.

Signed-off-by: Dusan Kostic <kostic.dusan1990@gmail.com>
[QRS detection] New test sample added

* Change:
  - New test sample, rec_2 added.
  - .gitignore file added

* Note:
  - rec_2 is created with rdsamp tool from:
    http://physionet.org/physiobank/database/edb/e0103
    recording.
  - Record is two hours in duration, sampled at 250Hz