Fix whitespace issues found by git diff --check, add gitattributes

Set per file type attributes in .gitattributes to fine-tune whitespace
checks.  With the associated cleanups, the tree is now clean for git

src/timezone/tznames/Australia.txt

@@ -60,4 +60,3 @@ WDT     32400 D  # West Australian Daylight-Saving Time (not in zic)
 WST     28800    # Western Standard Time (Australia)
                  #     (Antarctica/Casey)
                  #     (Australia/Perth)
-

src/timezone/tznames/Default

@@ -729,4 +729,3 @@ WAKT    43200    # Wake Time
 WFT     43200    # Wallis and Futuna Time
                  #     (Pacific/Wallis)
 YAPT    36000    # Yap Time (Micronesia) (not in zic)
-

src/timezone/tznames/Etc.txt

@@ -32,4 +32,3 @@ UTC         0    # Coordinated Universal Time
                  #     (Etc/UTC)
 Z           0    # Zulu
 ZULU        0    # Zulu
-