Add ability to build pod as a framework

cocoapods/libxlsxwriter-umbrella.h

@@ -0,0 +1,28 @@
+#import <UIKit/UIKit.h>
+
+#import "../xlsxwriter.h"
+#import "app.h"
+#import "chart.h"
+#import "common.h"
+#import "content_types.h"
+#import "core.h"
+#import "drawing.h"
+#import "format.h"
+#import "hash_table.h"
+#import "packager.h"
+#import "relationships.h"
+#import "shared_strings.h"
+#import "styles.h"
+#import "theme.h"
+#import "third_party/minizip/ioapi.h"
+#import "third_party/minizip/zip.h"
+#import "third_party/queue.h"
+#import "third_party/tree.h"
+#import "utility.h"
+#import "workbook.h"
+#import "worksheet.h"
+#import "xmlwriter.h"
+
+FOUNDATION_EXPORT double xlsxwriterVersionNumber;
+FOUNDATION_EXPORT const unsigned char xlsxwriterVersionString[];
+

cocoapods/libxlsxwriter.modulemap

@@ -0,0 +1,7 @@
+framework module xlsxwriter {
+  umbrella header "libxlsxwriter-umbrella.h"
+  header "../xlsxwriter.h"
+  
+  export *
+  module * { export * }
+}

libxlsxwriter.podspec

@@ -38,4 +38,9 @@ Pod::Spec.new do |s|
   s.header_mappings_dir   = "include/xlsxwriter"
   s.library               = "z"
   s.compiler_flags        = "-DNOCRYPT=1", "-DNOUNCRYPT=1"
+  s.pod_target_xcconfig   = { 'USER_HEADER_SEARCH_PATHS' => '${PODS_ROOT}/libxlsxwriter/include' }
+  s.module_map            = "cocoapods/libxlsxwriter.modulemap"
+  s.prepare_command       = <<-CMD
+                            cp cocoapods/libxlsxwriter-umbrella.h include/xlsxwriter/libxlsxwriter-umbrella.h
+                          CMD
 end