change default store, global bug fixes

Defaults to storing in memory instead of redis to make deployment
easier, Fixed an in issue with global when no posts are in the store
yet, also made sure maxid doesn't go under post id 1

dataaccess.caminte.js

@@ -13,7 +13,8 @@ var Schema = require('caminte').Schema;
 
 // set up the (eventually configureable) model pools
 // 6379 is default redis port number
-var schemaData = new Schema('redis', {port: 6379}); //port number depends on your configuration
+var schemaDataType = 'memory';
+var schemaData = new Schema(schemaDataType, {port: 6379}); //port number depends on your configuration
 
 // Auth models and accessors can be moved into own file?
 // so that routes.* can access them separately from everything!
@@ -217,7 +218,7 @@ setInterval(function () {
                     // dispatcher's output handles this for now
                     //process.stdout.write("\n");
                     // if using redis
-                    if (1) {
+                    if (schemaDataType=='redis') {
                       //console.dir(schemaAuth.client.server_info);
                       // just need a redis info call to pull memory and keys stats
                       // evicted_keys, expired_keys are interesting, keyspace_hits/misses
@@ -527,7 +528,15 @@ module.exports = {
     var count=Math.abs(params.count);
     var maxid=null;
     postModel.find().order('id','DESC').limit(1).run({},function(err,posts) {
-      maxid=posts[0].id;
+      if (posts.length) {
+        maxid=posts[0].id;
+      }
+      if (maxid<20) {
+        // by default downloads the last 20 posts from the id passed in
+        // so use 20 so we don't go negative
+        // FIXME: change to scoping in params adjustment
+        maxid=20;
+      }
       //console.log('max post id in data store is '+maxid);
 
       if (params.before_id) {