add conan shared builds

conanfile.py

@@ -10,6 +10,7 @@ class ImageMagickDelegates(ConanFile):
     settings = 'os', 'compiler', 'build_type', 'arch'
 
     options = {
+      'libtype': [ 'shared', 'static' ],
       'fonts': [ True, False ],
       'jpeg': [ True, False ],
       'png': [ True, False ],
@@ -38,6 +39,7 @@ class ImageMagickDelegates(ConanFile):
     }
 
     default_options = {
+      'libtype': 'static',
       'fonts': True,
       'jpeg': True,
       'png': True,
@@ -68,6 +70,11 @@ class ImageMagickDelegates(ConanFile):
     generators = [ 'CMakeDeps', 'CMakeToolchain', 'VCVars' ]
 
     def requirements(self):
+      if self.options.libtype == 'static':
+        default_options = { '*:shared': False }
+      if self.options.libtype == 'shared':
+        default_options = { '*:shared': True }
+
       # Fonts are not available on WASM targets
       if self.options.fonts and self.settings.arch != 'wasm':
         [self.requires(x) for x in ('libffi/3.4.4', 'fontconfig/2.14.2', 'freetype/2.13.2', 'fribidi/1.0.12', 'glib/2.78.1', 'harfbuzz/8.3.0')]