improve static linking check to allow dynamic linking to be specified on make...

improve static linking check to allow dynamic linking to be specified on make command, no need to hack libs.linux now to use dynamic linking, just use "make -f makefile.gtk KICAD_STATIC_LINK=0"

eeschema/plugins/makefile.gtk

@@ -4,7 +4,7 @@
 include ../../libs.linux
 
 # Use static link for libsupc++ (locate libstdc++.a and copy it in kicad_dev/syslibs)
-ifdef KICAD_STATIC_LINK
+ifeq ($(KICAD_STATIC_LINK), 1)
 #define path for a copy of libstdc++.a or/and libsupc++.a:
 LIBSTDC = ../../syslibs/libstdc++.a
 else

libs.linux

@@ -11,9 +11,9 @@ FINAL = 1
 #KICAD_PYTHON = 1
 
 
-# You must comment or uncomment this line for dynamic or static link
-# dynamic link is less difficult than static link
-# choose it if you have problems (libs not found, or unresolved references) ), or if kicad is running only on YOUR system.
+# You must comment this line for dynamic link (or build with "make -f makefile.gtk KICAD_STATIC_LINK=0")
+# dynamic link is less difficult than static link choose it if you have problems (libs not found, or
+# unresolved references), or if kicad is running only on YOUR system.
 ifndef KICAD_PYTHON
 KICAD_STATIC_LINK = 1
 endif
@@ -36,7 +36,7 @@ SUFFIX_WX_LIBGL = _gl-$(LIBVERSION).a
 
 # Use static link for libstdc++.a (sometimes also libsupc++.a)
 # locate libstdc++.a and copy it in kicad_dev/syslibs
-ifdef KICAD_STATIC_LINK
+ifeq ($(KICAD_STATIC_LINK), 1)
 #define path for a copy of libstdc++.a or/and libsupc++.a:
 LIBSTDC = ../syslibs/libstdc++.a
 else
@@ -49,7 +49,7 @@ LIBVERSION=`wx-config --release`
 LIBREGEX=$(WXPATH)/libwxregexu-$(LIBVERSION).a
 
 # use link static for wxWidgets
-ifdef KICAD_STATIC_LINK
+ifeq ($(KICAD_STATIC_LINK), 1)
 LIBS3D = $(WXPATH)/$(PREFIX_WX_LIBS)$(SUFFIX_WX_LIBGL)\
 	 $(MESALIBSPATH)/libGL.a $(MESALIBSPATH)/libGLU.a