fix bugs in base64.h

 INPUT:
Man is distinguished not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure..

 encodeBase64:
TWFuIGlzIGRpc3Rpbmd1aXNoZWQgbm90IG9ubHkgYnkgaGlzIHJlYXNvbiwgYnV0IGJ5IHRoaXMgc2luZ3VsYXIgcGFzc2lvbiBmcm9tIG90aGVyIGFuaW1hbHMsIHdoaWNoIGlzIGEgbHVzdCBvZiB0aGUgbWluZCwgdGhhdCBieSBhIHBlcnNldmVyYW5jZSBvZiBkZWxpZ2h0IGluIHRoZSBjb250aW51ZWQgYW5kIGluZGVmYXRpZ2FibGUgZ2VuZXJhdGlvbiBvZiBrbm93bGVkZ2UsIGV4Y2VlZHMgdGhlIHNob3J0IHZlaGVtZW5jZSBvZiBhbnkgY2FybmFsIHBsZWFzdXJlLi4=


 decodeBase64:
Man is distinguished not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure..