Move library source to src/ directory

Makefile.am

@@ -10,8 +10,7 @@ exposed = \
 	exposed/CDemo.c \
 	exposed/DOC.txt \
 	exposed/Makefile \
-	exposed/VbDemo.vb \
-	exposed/lib.cpp
+	exposed/VbDemo.vb
 
 EXTRA_DIST = \
 	$(exposed) \

src/Makefile.am

@@ -5,13 +5,13 @@ AUTOMAKE_OPTIONS = subdir-objects
 noinst_LIBRARIES = libslvs.a
 
 libslvs_a_SOURCES = \
-	../exposed/lib.cpp \
 	util.cpp \
 	entity.cpp \
 	expr.cpp \
 	constraint.cpp \
 	constrainteq.cpp \
-	system.cpp
+	system.cpp \
+	lib.cpp
 libslvs_a_CPPFLAGS = -DLIBRARY -I$(top_srcdir)/include
 
 AM_CPPFLAGS = $(FLTK_CXXFLAGS) $(LIBSPNAV_CPPFLAGS)