- made the header define longer (FSST_H => FSST_INCLUDED_H)
- made the header define longer (FSST_H => FSST_INCLUDED_H)

- substituted the (last) occurence of unaligned memory access by a memcpy.
  This usually does not come at a performance penalty, since compilers replace
  word-sized memcpy by simple load/stores on platforms that support
  unaligned memory access (i.e. most platforms)

- re-introduced FSST_MUST_ALIGN: a define that you *may* set if
  your platform does not allow unaligned memory access (note that all
  major platforms no support this very efficiently).

  Even if the platform requires aligned memory access, failing to set this
  will not break the correct functioning of fsst; however setting this
  define may help performance, as it surpresses code that only is fast
  when unaligned memory access is supported by the platform.

cwida/fsst,cwida/fsst,cwida/fsst,cwida/fsst