Allow C and Java native text spellings of NaN and infinities (#409)

C's printf doesn't output mixed case, while Java's Double.valueOf and
Double.toString parse/output only `Infinity`, not `Inf`. Rather than
requiring special-case code for both input and output in both languages,
relax the VCF specification to allow NAN/INF/INFINITY case-insensitively.

(Add "IEEE-754" to be specific and to improve the line breaks.)

VCFv4.3.tex

@@ -94,7 +94,9 @@ \subsection{Character encoding, non-printable characters and characters with spe
 
 
 \subsection{Data types}
-Data types supported by VCF are: Integer (32-bit, signed), Float (32-bit, formatted to match the regular expression \verb|^[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?$|, \texttt{NaN}, or \texttt{+/-Inf}), Flag, Character, and String.
+Data types supported by VCF are: Integer (32-bit, signed), Float (32-bit IEEE-754, formatted to match one of the regular expressions \verb|^[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?$| or \verb"^[-+]?(INF|INFINITY|NAN)$" case insensitively),%
+\footnote{Note Java's {\tt Double.valueOf} is particular about capitalisation, so additional code is needed to parse all VCF infinite/NaN values.}
+Flag, Character, and String.
 For the Integer type, the values from $-2^{31}$ to $-2^{31}+7$ cannot be stored in the binary version and therefore are disallowed in both VCF and BCF, see \ref{BcfTypeEncoding}.
 
 \subsection{Meta-information lines}