Touch: Make -d accept more complex date format

[GrayJack]

Is your feature request related to a problem? Please describe.
All other implementation accept more complex date strings, right now this implementation is YYYY-MM-DD hh:mm:ss]

Describe the solution you'd like
All other implementation accept YYYY-MM-DDThh:mm:SS[.frac][tz] where

• YYYY: At least four decimal digits representing the year.
• MM, DD, hh, mm, SS: As with -t time.
• T: The letter T or a space is the time designator.
• .frac: An optional fraction, consisting of a period or a comma followed by one or more digits. The number of significant digits depends on the kernel configuration and the filesystem, and may be zero.
• tz: An optional letter Z indicating the time is in UTC. Otherwise, the time is assumed to be in local time. Local time is affected by the value of the TZ environment variable.

Describe alternatives you've considered
Let as is, but break compatibility with other coreutils touch tool.