Implemented better support for the compression library libaec.
Especially, for the new version 1.0.5:
- The CMake config files of this version 1.0.5 now set certain
  SZIP variables which can be used in the existing
  CMake structure.
- Both static and shared SZIP compatible libaec library contains
  all required objects such it can be easily used when building
  HDF5 from scratch.
- Introduced the USE_LIBAEC_STATIC option to make use of the static
  version of SZIP compatible libaec library.

Implemented the fallback option for the case if version 1.0.5
of libaec could not be found.

Added short description about the libaec improvement to the Bug Fixes
section in the Configuration sub-section.