Added CImplementations folder (C code only)
Closes #23
Updated DeleteNodeLinkedList.java, TestDeleteNodeLinkedList.java and Node.java
Created Stack API
Closes #27
Created Chapter3 subfolder
Closes #27
all single linkedlist exercises
Added: tree API, bubbleSort and selectionSort (with tests)
Closes #32
Closes #35
Closes #40
Closes #46
Closes #34
Added: quicksort.c and testQuickSort (In-Place QuickSort)
Removed: unused function merge
Added: mergeSort.c and testMergeSort.c
Closes #25 and #30
Closes #13 and #14
Closes #20
updated: stack.c (added peek and isEmpty methods)

added: sortStack.c and testSortStack.c

Closes #31
Merge branch 'origin/carol'