Merge pull request #6 from mcna/master

Bug fix for timestamp-whole-year difference
Fixed compiler notes and an incompatibility with asdf3
New version of local-time 1.0.4
Abstract out the notion of a clock
Update INSTALL docs for quicklisp and test instructions
Specialize on t rather than empty system-clock
Include clock API in documentation
Convert tabs to spaces
Fix issue with STRING subtypes.

Which allows (parse-timestring (format-timestring nil (now))) to work
again (tested on SBCL 1.1.6.12, CLISP 2.48) where it previously raised
an error on SBCL because FORMAT-TIMESTRING returns a SIMPLE-BASE-STRING:

debugger invoked on a TYPE-ERROR in thread
  The value "2013-04-16T23:44:28.910375+02:00"
  is not of type
    (SIMPLE-ARRAY CHARACTER (*)).

Since the UPGRADED-ARRAY-ELEMENT-TYPE for BASE-CHAR and CHARACTER may
differ, (SUBTYPEP 'SIMPLE-STRING '(SIMPLE-ARRAY CHARACTER (*))) can be
true or false between implementations, so %SPLIT-TIMESTRING has to
use SIMPLE-STRING (and CHARACTER).
Merge pull request #9 from Ferada/small-fixes

Fix issue with STRING subtypes.
Switched to non-hu.dwim version of stefil for testing
Timestring parsing now supports an offset without a separator

This addresses issue #11.
Fixed offset parsing tests
Timestamp comparisons now raise a type-error condition on non-timestamps

Resolves issue #12
Merge pull request #7 from cddr/develop

Abstract out the notion of clocks
add test to cover weekday adjust-timestamp bugfix
fix bug in adjust-timestamp for weekdays in next month

previously, if a day-of-week adjustment was made into the following months,
an error was raised.