Fixing the memory, adding a shell, and other minor bugs to gdt and idt and the types, also adds .github files for bug reports and feature requests.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,15 @@
+---
+name: Bug report
+about: Create a bug report to help us improve 88os
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+If you found a bug in 88os, please provide:
+
+1) A clear and concise description of what the bug is: what happened and what you expected to happen.
+2) Steps to reproduce the bug.  Ideally, you would provide a small code example triggering the bug and the exact command line used to run KLEE.  Please make sure the bug is still present in the mainline.
+3) The warnings and error messages issued by KLEE
+4) Any relevant information about your platform: the output of `klee --version`, OS version, environment variables, directory in which KLEE is run, etc.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,14 @@
+---
+name: Feature request
+about: Suggest a feature in 88os
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is.  E.g., I find it difficult to use KLEE when [...]; I would find it very useful for 88os to [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.