Framework code for HpLRU

1. Integrate GNU libtool to build HpLru shared/static object.
2. Core implementation for HpLRU; Concurrent LRU with support to hook
   user defined hash map and a custom concurrent double linked list.
3. Framework code to leverage HpLRU classes. Data layout is inspired
   by NoSQL data layout.

	 |<---- Row-Bucket-------------->|
    _____________________________________
   |	 |key1|key2|		   |keyn |
   |Row-1|    |	   |		   |	 |
   |_____|____|____|_______________|_____|
   |	 |				 |
   |	 |				 |
   |_____|_______________________________|

   Each Row is identified by a unique-key. Each row holds a bucket
   of <key,value> pairs. The capacity of bucket is user-defined, the
   keys life within a bucket is determined by LRU policy.