Merge pull request #681 from tritao/dll-api

Added public API visibility macros

diff --cc mono/metadata/marshal.c
Simple merge

diff --cc mono/metadata/marshal.h
Simple merge

diff --cc mono/metadata/metadata-internals.h
Simple merge

diff --cc mono/metadata/object-internals.h
Simple merge

diff --cc mono/mini/decompose.c
Simple merge

diff --cc mono/mini/method-to-ir.c
Simple merge

diff --cc mono/mini/mini.h
Simple merge