Detect shell at runtime.
Detect shell at runtime.

Test whether the shell is a POSIXy or Windows shell based on the
spelling of "/dev/null", rather than inferring it at compile time with
macros.

git-svn-id: 33c1020af00f61ce75d0fe36814d3322ab23371a@1347834 13f79535-47bb-0310-9956-ffa450edef68

kidaa/lucy,apache/lucy,rbevers/lucy,apache/lucy,pombredanne/apache-lucy,kidaa/lucy,rectang/lucy,nwellnhof/lucy,apache/lucy,rbevers/lucy,kidaa/lucy,rectang/lucy,rbevers/lucy,apache/lucy,nwellnhof/lucy,rbevers/lucy,pombredanne/apache-lucy,kidaa/lucy,nwellnhof/lucy,kidaa/lucy,nwellnhof/lucy,pombredanne/apache-lucy,rbevers/lucy,pombredanne/apache-lucy,rbevers/lucy,rectang/lucy,rectang/lucy,rectang/lucy,rectang/lucy,apache/lucy,pombredanne/apache-lucy,apache/lucy,rectang/lucy,nwellnhof/lucy,nwellnhof/lucy,apache/lucy,kidaa/lucy,rbevers/lucy,pombredanne/apache-lucy,pombredanne/apache-lucy,kidaa/lucy,kidaa/lucy,nwellnhof/lucy