Please add support for Cygwin platform

[lynnboy]

Let's apply a couple of lines:

$ git diff build/Jamfile.v2
diff --git a/build/Jamfile.v2 b/build/Jamfile.v2
index af8de28..855fd35 100644
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -47,6 +47,7 @@ local rule default_binary_format ( )
     local tmp = elf ;
     if [ os.name ] = "MACOSX" { tmp = mach-o ; }
     if [ os.name ] = "NT" { tmp = pe ; }
+    if [ os.name ] = "CYGWIN" { tmp = pe ; }
     if [ os.name ] = "AIX" { tmp = xcoff ; }
     return $(tmp) ;
 }
@@ -65,6 +66,7 @@ local rule default_abi ( )
 {
     local tmp = sysv ;
     if [ os.name ] = "NT" { tmp = ms ; }
+    if [ os.name ] = "CYGWIN" { tmp = ms ; }
     else if [ os.platform ] = "ARM" { tmp = aapcs ; }
     else if [ os.platform ] = "MIPS" { tmp = o32 ; }
     return $(tmp) ;

[olk]

please provide a patch and run the unit-tests (!)

[lynnboy]

Sorry, I've run boost/context/test/ and both tests are passed.

I failed to attach a file in a github issue (what's wrong with github?), but the total change is the specified two lines.

The os.name reported for Cygwin is different than both MSVC and MinGW, but their binary format and ABI are just the same.

[olk]

done