Ditz issue update
Fix DUK_INVALID_INDEX define
Release note: DUK_INVALID_INDEX define
Merge branch 'api-invalid-index-fix'
Bug testcase for Duktape.gc() return value
Guide comment: Duktape.gc() retval unspecified
Fix Duktape.gc() return value
Release note: Duktape.gc() return value
Merge branch 'duktape-gc-retval-fix'
Ditz issue update
Ditz issue update
Ditz issue update
Add OS and compiler to Duktape.env
Fix DUK_F_CLANG detection to avoid also DUK_F_GCC

Before this fix, both DUK_F_GCC and DUK_F_CLANG would be defined when
compiling with clang.  This might have had an impact on the #ifdef
ladders in duk_features.h.in so that this change may have some side
effects for clang.
Update Duktape.env example in guide
Release note: OS and compiler in Duktape.env
Improve Duktape.env example in guide
Merge branch 'compiler-os-duktape-env'
Ditz issue update