updated readmes and added linux build scripts

linux/deb_get_prereqs.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+#
+# Install prerequisite packages for SonoBus build on Debian based distros
+
+GITREPO="https://github.com/essej/paulxstretch.git"
+
+PREREQS="libjack-jackd2-dev \
+    libasound2-dev \
+    libx11-dev \
+    libxext-dev \
+    libxinerama-dev \
+    libxrandr-dev \
+    libxcursor-dev \
+    libfftw3f-def \
+    cmake
+    "
+FREETYPES=$(apt-cache pkgnames libfreetype)
+if [[ $FREETYPES == *"libfreetype6-dev"* ]]; then
+      PREREQS+="libfreetype6-dev "
+elif [[ $FREETYPES == *"libfreetype-dev"* ]]; then
+      PREREQS+="libfreetype-dev "
+else
+    echo "Couldn't find libfreetype dev package"
+    exit 1
+fi
+if [[ $(apt-cache pkgnames libcurl4-openssl-dev) == *"libcurl4-openssl-dev"* ]]; then
+      PREREQS+="libcurl4-openssl-dev"
+elif [[ $(apt-cache pkgnames libcurl4-gnutls-dev) == *"libcurl4-gnutls-dev"* ]]; then
+      PREREQS+="libcurl4-gnutls-dev"
+else
+    echo "Couldn't find libcurl ssl/tls dev package"
+    exit 1
+fi
+
+
+
+
+echo ""
+echo "Installing prerequisites - " $(date)
+echo ""
+
+sudo apt update
+
+sudo apt -y install git build-essential $PREREQS
+
+function ver { printf "%03d%03d%03d%03d" $(echo "$1" | tr '.' ' '); }
+
+cmakever=$(cmake --version | head -1 | cut -d" " -f3)
+
+if [ $(ver $cmakever) -lt $(ver 3.16) ] ; then
+  echo "Your CMake is too old! You need version 3.16 or higher. Try to get a newer version, or compile CMake from source."
+  exit 1
+fi