Adding fetch_params.bat and dependency for verus-cli for Windows

.gitignore

@@ -1,6 +1,5 @@
 *.tar.gz
 *.deb
-*.exe
 src/bitcoin
 src/zcashd
 src/zcash-cli

kmd/windows/verus-cli/fetch-params.bat

@@ -0,0 +1,21 @@
+@echo off
+call :GET_CURRENT_DIR
+cd %THIS_DIR%
+IF NOT EXIST %APPDATA%\ZcashParams (
+MKDIR %APPDATA%\ZcashParams
+)
+IF NOT EXIST %APPDATA%\ZcashParams\sprout-proving.key (
+    ECHO Downloading Zcash trusted setup sprout-proving.key, this may take a while ...
+    .\wget64.exe --progress=dot:giga --continue --retry-connrefused --waitretry=3 --timeout=30 https://zensystem.io/downloads/sprout-proving.key -O %APPDATA%\ZcashParams\sprout-proving.key
+)
+IF NOT EXIST %APPDATA%\ZcashParams\sprout-verifying.key (
+    ECHO Downloading Zcash trusted setup sprout-verifying.key, this may take a while ...
+    .\wget64.exe --progress=dot:giga --continue --retry-connrefused --waitretry=3 --timeout=30 https://z.cash/downloads/sprout-verifying.key -O %APPDATA%\ZcashParams\sprout-verifying.key
+)
+goto :EOF
+:GET_CURRENT_DIR
+pushd %~dp0
+set THIS_DIR=%CD%
+popd
+goto :EOF
+