Improve cmake files for building on Android

Signed-off-by: William Brawner <me@wbrawner.com>

src/CMakeLists.txt

@@ -25,42 +25,46 @@ set(PIHELPER_SOURCES
     )
 
 include_directories(/usr/local/include)
+if (NOT TARGET CURL)
     find_library(
         CURL
         NAMES curl libcurl
         HINTS /usr/local/lib /usr/local/lib64 /usr/lib /usr/lib64
         )
+    if (NOT CURL)
+        message(SEND_ERROR "Did not find curl")
+    endif()
+endif()
+if (NOT TARGET JSONC)
     find_library(
         JSONC
         NAMES json-c libjson-c
         HINTS /usr/local/lib /usr/local/lib64 /usr/lib /usr/lib64
         )
+    if (NOT JSONC)
+        message(SEND_ERROR "Did not find json-c")
+    endif()
+endif()
+if (NOT TARGET CRYPTO)
     find_library(
         CRYPTO
         NAMES crypto libcrypto
         HINTS /usr/local/lib /usr/local/lib64 /usr/lib /usr/lib64
         )
+    if (NOT CRYPTO)
+        message(SEND_ERROR "Did not find OpenSSL")
+    endif()
+endif()
+if (NOT TARGET OPENSSL)
     find_library(
         OPENSSL
         NAMES ssl libssl
         HINTS /usr/local/lib /usr/local/lib64 /usr/lib /usr/lib64
         )
-
-if (NOT CURL)
-    message(SEND_ERROR "Did not find curl")
-endif()
-
-if (NOT JSONC)
-    message(SEND_ERROR "Did not find json-c")
-endif()
-
-if (NOT CRYPTO)
-    message(SEND_ERROR "Did not find OpenSSL")
-endif()
-
     if (NOT OPENSSL)
         message(SEND_ERROR "Did not find OpenSSL")
     endif()
+endif()
 
 option(PIHELPER_STATIC "Build Pi-Helper as a static library" ON)
 option(PIHELPER_SHARED "Build Pi-Helper as a shared library" OFF)
@@ -85,7 +89,7 @@ if (PIHELPER_STATIC)
         )
 
     install(TARGETS libpihelperstatic
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
         )
 endif()