Low-hanging fruit: get out a bunch of old-style for loops,

... mostly in main programs. Hope none were over-zealous!
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#	modified:   environ/SysPropDemo.java
#	modified:   regex/GrepNIO.java
#	modified:   strings/EnTab.java
#	modified:   strings/Fmt.java
#	modified:   strings/SoundexSimple.java
#	modified:   strings/StrCharAt.java
#	modified:   strings/StrTokDemo4.java
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