[New] Supercharge nvm debug output

Try to get shell version, OS and its version, curl/wget version.

nvm.sh

@@ -2249,6 +2249,35 @@ nvm() {
       nvm_err "\$NPM_CONFIG_PREFIX: '$(nvm_sanitize_path "$NPM_CONFIG_PREFIX")'"
       nvm_err "\$NVM_NODEJS_ORG_MIRROR: '${NVM_NODEJS_ORG_MIRROR}'"
       nvm_err "\$NVM_IOJS_ORG_MIRROR: '${NVM_IOJS_ORG_MIRROR}'"
+      nvm_err "shell version: '$(${SHELL} --version | command head -n 1)'"
+      nvm_err "uname -a: '$(uname -a)'"
+      if [ "$(nvm_get_os)" = "darwin" ] && type sw_vers > /dev/null; then
+        nvm_err "OS version: $(sw_vers | command awk '{print $2}' | command xargs)"
+      elif [ -r "/etc/issue" ]; then
+        nvm_err "OS version: $(command head -n 1 /etc/issue | command sed 's/\\.//g')"
+      fi
+      if nvm_has "curl"; then
+        local CURL
+        if type curl | command grep -q hashed; then
+          CURL="$(type curl | command sed -E 's/\(|)//g' | command awk '{print $4}')"
+        elif type curl | command grep -q aliased; then
+          CURL="$(type curl | command awk '{ $1=$2=$3=$4="" ;print }')"
+        else
+          CURL="$(type curl)"
+        fi
+        nvm_err "curl: ${CURL}, $(command curl -V | command head -n 1)"
+      fi
+      if nvm_has "wget"; then
+        local WGET
+        if type wget | command grep -q hashed; then
+          WGET="$(type wget | command sed -E 's/\(|)//g' | command awk '{print $4}')"
+        elif type wget | command grep -q aliased; then
+          WGET="$(type wget | command awk '{ $1=$2=$3=$4="" ;print }')"
+        else
+          WGET="$(type wget)"
+        fi
+        nvm_err "wget: ${WGET}, $(command wget -V | command head -n 1)"
+      fi
       local NVM_DEBUG_OUTPUT
       for NVM_DEBUG_COMMAND in 'nvm current' 'which node' 'which iojs' 'which npm' 'npm config get prefix' 'npm root -g'
       do