strftime now handles all standard conversions, in the C locale. 'Z' is ignored (no time zone name available).

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2363 1084037a-409f-4a99-8160-1a4b3577d4c1
New file and function iso_weeknum. This was added to support strftime(), but may be useful in its own right.

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2364 1084037a-409f-4a99-8160-1a4b3577d4c1
Various functions should have had parameters declared 'const'.

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2365 1084037a-409f-4a99-8160-1a4b3577d4c1
Updated time.h for new function iso_weeknum(), and made several parameters const. Expanded the overview with a more complete description, detailing the few departures from the standard, and edited some comments for clarity.

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2366 1084037a-409f-4a99-8160-1a4b3577d4c1
Corrected the name of the iso week number function.

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2367 1084037a-409f-4a99-8160-1a4b3577d4c1
Copied and pasted the wrong line.

git-svn-id: http://svn.savannah.nongnu.org/svn/avr-libc/trunk@2368 1084037a-409f-4a99-8160-1a4b3577d4c1