Return the current string cropped by number of words or characters.
Words: returns the first "xNumber" of words in the string, including any intermediate punctuation, etc. Trailing punctuation is always removed.
Characters: returns the first "xNumber" of characters in the string, including any intermediate punctuation, etc. When it locates the last character, it scans ahead to make sure it's not breaking a word. If it is in the middle of a word, it will skip ahead to the next non-alpha-numeric chatacter and break on that, so your cropped string may be slightly larger than the number of characters you requested. Trailing punctuation is always removed.
